Can someone help me? I'm really disturbed. I promise I'm not a troll?

Me and my boyfriend are expecting our son next month. His ex that he dated before he dated me is really obsessive over him. Every day on her twitter she puts its been so many days since my husband has talked to me and its up to 87. She moved away to another state also.She started harassing me on facebook, telling me how if anyone was going to have his baby it was going to be her. This kinda disturbed me so I just blocked her. Well I posted a picture of one of my ultrasounds on twitter because only a few of my close friends have a twitter and they wanted to see my son. I was also unaware that lissa had a twitter at the time. When I found out she had a twitter and had been looking on mine posting things about me I unblocked her on facebook. When I did this, I went to her profile page and saw a picture of my ultrasound, my name had been blacked out and she was telling everyone how this was her and my boyfriends child. She is also telling everyone where she lives now that she is pregnant and is claiming she is due on my due date and engaged to my boyfriend. What do I do? my boyfriend doesn't speak to her. Please help.