I'm 30 weeks pregnant and I keep having really bad abdominal pain that lasts for several minutes in…

I'm 30 weeks pregnant and I keep having really bad abdominal pain that lasts for several minutes in the middle of sex.. I know this is kinda personal but this is my first child. I don't think this is normal. I was in terrible pain last night and earlier today. except last night I couldn't even move and my back was hurting and I was having contractions(possibly braxton hicks contractions) WHILE the abdominal pain was happening.. any opinions? is this shit normal???