How can I feel secure with him?

Well I guess I should start from the beginning, I started seeing this guy in Jan and he asked me from the start where is this going because he didn't want to be led on. I knew I should have said I don't know yet we are just getting to know each other but I said yes because he asked me out. So now we are a couple, in Feb I find out I'm pregnant. He got all scared and didn't know what to do and said he wasn't ready, we talked about abortion I set up the appointment and couldn't go through with it. He couldn't come with me that day because he had school that day and had a test and had to hand in an essay , I couldn't do it alone and I told him that. I went alone and cried and left. I am in university aswell but I managed to set it up with my profs to let them know I wouldn't be able to make it why couldn't he? Anywayz we booked another appointment and I couldn't do it. I couldn't kill my kid regardless because I already have a child. He is in grad school now and he felt that this would be too much and the fact that we don't know each other yet he wondred if it was even his, but it is. Now he started distancing himself a bit, this is where the story really starts, I was told about FACEBOOK by my friends and found out he was on it, I tried to add him as my friend and he wouldn't add me . I asked him why time and time again. I said am I a secret you have other girls on her but you wont add me? I said what are you leading a double life. He told me maybe he is being secretive. So I looked on his friends list and saw this 1 girl who stood out I messaged her and asked her in a way to see how she knew him , she said her sister does more then her. So I messaged her back and asked her thinking she did know him what I should do because I'm pregnant to ffind out more about him to see what he was hidding,and she said replied she didn't really know him , so I said well he has you on his list so you must know something cause her sister wasn't even on it. Then she blocks me. I'm pregnant so my hormones have me thinking a whole bunch of scenarios, I got into his MSN and pretend I was him and talked to this girl on his MSN , I said we should meet up and she was like yea because we never met she gave me her number and we set up a time to meet. I get an email later on from the same girl with a different EMAIL though, saying "hey baby..... I changed my number add me. I add her and its the same pic as the girl from the facebook mind you the girl I talked to on MSN had a pic of lips not her face. At the time I didn't put that toghether and automatically assumed it was her. I talked to this girl for 2 hours, I pretend I was him until later on in the convo,she ends up telling me she was his girlfriend for 7 years, that on the 30th they were going to France and he got a law internship there and her dad bought them a house and she bought his car and is paying his insurrance....I said what about his ex girl of 5 years she said that must be her..I say well whats your background to make sure cause his ex is white she says balck and white like the pic. She tells me she needed to get into his MSN so she can make the last payment and close the account. I said give me your number and I will give you the password. I felt bad for her now and she told me I could get back in after. So what am I supposed to think? I call him and said how could you lie to me I knew something was up, he denied it adn said it wasn't true. I call the number and it went straight to a voice mail but then I looked at the number the original girl from face book gave me and the last number was different so I call it... I say hey you said I could call you so we could talk about this she didn't know what the hell I was talking about but she sounded like she genuinely didn't know what I was talking about, so I appologized and hung up. I talk to him again told him what happened cause by then he knew I got into his account, he said he though he knew who did it. I t was his ex of 5 years the white girl (sorry I don't know her name). I left it alone and he was upset I did this to his stuff. after week we finally resolved this he came over for the weekend we had a great time. Then last night he calls me to say that he talked to the girl from facebook and she said how she talked to me on msn and gave her number again thinking I was him and that I called her on top of it. I told him I already said I did that minus tthe msn convo. His exs tell him "oh how he saved him from me "and sent him what we talked about.. She lied just like me and played with my mind for 2 hours I threw up for god sake on this and I'm pregnant. Its my fault that was my Karma I should have never done this. He told me he doesn't listen to her anyways and that I was looking more and more like her and thats why they broke up. I just felt very vulnerable bacuse he was being secretive. He said this is all new to him and he needed time to adjust that sounds better then "yeah maybe I am being secretive". He said I was being to presumptuousand that I jumped to conclusions. My hormones are have me up and down and I just wanted to have a sense of security with him. So he tells me he can't talk about this anymore and that he would call me today but now I know I feel it inside , things will never be the same and I lost his trust. I even said a week ago after this that I don't even want the msn again and I f I did something like this again I don't want to be a person like that, but after last night I wonder if he thinks thats it something else findidng out I talked to the girl From FACEBOOK aswell... This is probbaly really confusing to who reads this but if you can give me advice on what I should do now it would be greatly appreciated. I know what I did was wrong no denying it but I want this to work out so bad , I wonder if maybe I should put the baby up for adoption.