need some advice on my pregnant girlfriend

I met my girlfriend and we hit it off right away. She is 28 and i am 29. From the day we met we spent every day together for 45 days, and fell in love. She was on birth control for 10 years and never got pregnant but for some reason she happened to get pregnant probly the first time we had sex ( 2 weeks after we met). Now when we found out we were both very happy and decided right away to have the child but about a week after that she started to become very cold towards me, stopped saying she loves me ect. One day she asked me thru text for some space, she just wanted to be friends right now and that she needed to figure things out and her life had been turned upside down in a matter of weeks, i told her no problem even tho i really didnt understand and she offered no explaination at all i told her will be here but as time passed i started to miss her and texted her a couple times to try and work things out together but that just made her run farther away. We have never really agrued about anything. She wanted none of that and now if i even bring up why she doesnt want to see me or that i just want to be here to help she says we talked about this and gets mad. As of today she is 12 weeks along and i have not seen her for a month and it seems she could care less about anything i feel. it is like she just shut me out of her life for no reason at all. I know that if she hadnt gotten pregnant we would still be a happy couple. I love her so much, this last month has been the absolute worse of my entire life. Im so confused, i would marry this girl in a second if only she would just talk to me. Should i just stop calling her and hope she comes around or keep tryin to get her to hang out with me so we can talk face to face. When it comes down to it i miss her and she doesnt miss me at all, i havent seen her in a month and day after day it seems she gets farther away from me Any advice that anyone could give me would be greatly apperiated.