Help! Cramps and super heavy flow


Hey! So just over a week ago I got my period. It was super light and only lasted about 3 days (mine always last about 5-6). Now, today I woke up with some light bleeding. Dark brown with lots of discharge. I put on a panty liner and went to work. 20 minutes into my shift I started getting horrible cramps, like in my stomach and lower back to the point where I broke out into a sweat and felt like vomiting. I went to the bathroom and had bled through my panty liner big time so I put in a heavy flow tampon. I bled through it in an hour and have switched my tampon four times since then because I completely bled though them. Again, super dark blood with quite a bit of discharge and I am in a lot of pain. I feel like I need to go to the clinic tomorrow if this is still happening but I would like to know if anyone has experienced this before and if it's normal.