Bleeding after sex

I'll be 17 weeks tomorrow and for the past 5 weeks sex has been fine- no bleeding it just feels very tight and honestly unenjoyable. Well this morning of course I let him do what he wanted and I went pee about 20 min later and boom bright red when I wiped. 2nd time I wiped there was a blood clot. Naturally I freaked out and just stared at it. Eventually wiping it got darker and less and less was on the paper. Should I just wait it out and see if it continues or should I go to the er? I have no cramping at all just the shocking spotting. Any advice? Thanks!