Grandparent's rights..?

Britney
Okay so I live in the state of Pennsylvania. I'm 19 years old (will basically be 20 when i deliver) and I've been living on my own for a year now. I've been married since September. My husband and i live on our own and pay all our own bills. We do not recieve any help from the government and I'm 26 weeks pregnant. So basically my mom kicked me out when I was 18 because she wanted to live with her friends. She's always been a bad parent. She was in jail for 18 months and i lived with my aunt. Ever since I got pregnant she's been extremely annoying about seeing my son that is not even here yet. She said if I don't let her see him when she wants she is taking me to court for grandparents rights and she will get him one weekend a month. She claims that even if I move away the court will make me bring my son to her no matter where i live. She's threatened to call children and youth on me after my son is born because I have a bad driving record (a few small accidents and tickets when I was 16) plus I got a speeding ticket while pregnant. She even thinks she can get a court order to be in the delivery room when he comes. I'm so annoyed and beyond my breaking point dealing with her. She threatens me that she will show up to my baby shower and ruin it just cause she feels like it. My question is does she legally even have rights to see my son? Also what if she does call children and youth on me..? I don't do anything wrong I don't do any drugs or drink and I'm quitting my job to be a stay at home mom so I can care for my son 24/7. I'm so worried about all of this.