Breast soreness, light cramps and spotting

Tatiana

My period ended a few days ago so after my cycle my boyfriend and I had some fun. Yesterday I started to have tender breast and slight cramps at work so I went to the bathroom and saw I was spotting darker brown blood. This is a first for me and I don’t know what to do about it because I still have tender breast. Can anyone help? This has never happened to me before.