I don't know what to think😕

I have been taking Fertilaid for 1 month and I never got a positive opk. I could of still ovulated but i never got my positive so im not 100% sure if i did ir didnt.We have been doing the baby dance every other day since CD 10 and today is CD 19 and I just went to the bathroom and there was dark brown(I'm assuming) blood in my underwear. I know these supplements are messing with my cycle a little bit so idk if it's an early period or if I should be worried. I have never experienced this before.