hey, for the past couple of weeks my boobs have been super sensitive, and have been feeling tired with back ache. I have been pregnant before and had all this after just 2 weeks. so I did think it was that, but the pregnancy test was negative. now, about 4 days after the pregnancy test, I've started heavily bleeding, and it's bright red and not thick at all, along with some serious cramps. I've never had a period like this before ! it's not 'normal' for me. I've only been bleeding for a couple of hours, but it's causing a lot of pain, and it's so heavy !
I'm 18/19 so cramps aren't anything new, but this time it's really bad. and I'm engaged so me and my fiance are frequent in the bedroom department, but we're not trying for a baby

help ???