Huge clot

Will try to keep this short and sweet.

I had my son 13 months ago

Copper iud 11 months ago, I seriously love it

Breastfed until December 2nd

Started this period December 6th. It started with light brown discharge/spotting, progressed into a normal period. Thought it was starting to end but it got heavier instead. The cramps picked up to the point where, now, otc pain relief doesn’t help. It takes the edge off where I can still function, but the pain never completely disappears. I went to my OBGYN yesterday where I talked to a NP (my OB is out of office until Tuesday, and I couldn’t take the pain and constant bleeding anymore). She prescribed me Provera for temporary relief. I took the first pill yesterday December 27 and the second today December 28. I’m still bleeding and cramping the same (obviously meds take time, I know that, I have taken provera before a few years ago for a different problem). About ~10 minutes after taking the second pill, I went to the bathroom to change my pad before bed. I passed this clot (picture below, be warned). I have never had clots during my period in my entire life and definitely nothing like this. Earlier today (~12-1pm), I was having awful radiating cramps that came and went in waves VERY similar to early labor contractions (pain for 1-2 minutes, no pain for a few minutes, pain for 1-2 minutes, no pain for a few, etc. etc.), but then they went away after a little bit and nothing out of the ordinary happened the rest of the day/night. Until this around 10pm. I am currently not in any pain, and I feel completely fine. I am calling my doctor tomorrow. In the meantime, for anyone who has dealt with anything similar, what could this mean?