7 weeks PP cramping

Was hoping to hear from anyone that may be experiencing what I am. I had an 8 day heavy period on July 10th and since then have had horrible cramping. I've been seen by my OB for a possible infection but nothing was found. I was told that given it's baby #3 for me its taking me awhile to go back to some kind of normalcy. I was told to take 800mg of ibuprofen every 8 hours to manage my pain but no change in 3 days. I'm miserable.