31 weeks and BLEEDING... HELP!!!

I am 31 weeks and 5 days I have been  bleeding (every day) and having blood clots (on and off) for about 5 days. The last time I had sex was on Sunday and this is when it all started. I've been having mild to heavy cramps the baby has been moving normal. The last time I went to the hospital was because of bleeding and the cause was sex, but it stopped after 1 day. This is my first pregnancy and I'm getting worried that something may be wrong, but then I don't want to waste the doctors time if nothing is wrong.... I NEED HELP!!!!