Three months late.

Alright here we go, I haven't had a period in a little over three months. I'm not stressed or anything at least i don't think. Nothing has changed or been irregular with my life. I've taken three pregnancy tests that have all came back negative. In the past three months I've gained about fifteen pounds and have started getting stretch marks on my breasts. Recently I started feeling super sick to my stomach and getting sharp pains. I haven't been to worried about being pregnant because stressing out about it will only make it worse and Ive had a late period before but not more than a week. The only reason I am actually a little concerned now is that I train for mma and i have a fight coming up on November which it has seemed IMPOSSIBLE for me to cut my weight. I have a doctors appointment coming up for it but I was just curious if anyone else had any ideas. I am only concerned due to the fact that I do get kicked and hit in practice and if I was pregnant I would not want to risk injury.