39 weeks and sick?

I am 39 weeks pregnant with my first and I started having menstral like pains in my lower stomach. They have seem to got worse but I also have a bowel movement or feel like that is what it is. So I dont know what the pain is from. I do have lower back but not real bad. Just my stomach hurts real bad like I am having a bad period. And it doesnt seem to come and go all the time sometimes it seems like it stays just hurts more one minute and not so much the next minute. On top of all this I am really congested and the Dr gave me antibiotics and I have been getting nauseated. I dont know if the nausea is comeing from the pills or the pain in my stomach. It is hard to move around cause there is so much pressure down there it hurts! Should I go to the hospital or will this just p??