22y.o. Sexually active- On birth control but have been on and off bleeding for 3 weeks and this past week has been heavier bleeding than I’ve ever had (changing tampon every hour or less and it still bleeds through ) and bad cramping. Passed this today and it’s a round sac when unfolded- almost entirely sealed all the way around (empty like a pocket) except for a hole at the top and blood came out of it. It’s smooth on the outside and bumpy/ textured inside. What is this? Does anyone know? /Should I see a doctor? ;-; thanks!