Ladies!! Help please!!

Okay.. so I ovulated I believe on the 7th due to opks and a slight string of blood in ewcm one time when I wiped. I didn't spot or anything until today. I noticed it this morning when I wiped.. it was light brown and every time I go to the bathroom. By the end of the night tonight I noticed that my underwear had some brown spotting on it. I'm only 3dpo and I'm not sure what's going on. I think I'm extra nervous about an MC due to having one last August. Can any of you ladies give me some insight on what it might be? Could it be IB already??