Starting BC after miscarriage

Hello everyone, I just started BC for the first time on Sunday 07/07. I had a positive pregnancy test 06/14 & started bleeding 06/17 & received the news of miscarriage on 06/21. They estimated I was super early due to not being able to see anything, & last period had been 04/26. I am super irregular & started BC to try & regulate it.

Question: has anyone used BC after miscarriage?

Also, since I just started, could I already be experiencing weight gain & sadness? Felt the need to cry ( but couldn’t/ didn’t allow myself) as I was at work.

Thanks in advance!