Ovulation! ! PLEASE HELP

Ok well I haven't had sex since march. And I have been getting my periods like normal. and during ovulation I always get brown discharge every month. This month I had more brown discharge charge then normal. I did have a heavy flow last month. I can't be pregnant I haven't had sex. Although I did do oral but I made sure no cum was near me. I had my pants on the whole time. and I washed My hands. anyways I'm having brown discharge. so much that it leaves a mark in my underwear? plz help me it's been happening for to days now.