We’ve been trying to conceive ..

I’m just wondering has any ladies experienced this...My period is supposed to be on right now and well it’s been on for a week but.. it’s not on. It’s EXTREMELY light like not even enough for a pad. I only see a little blood when I wipe and that’s not every time so I can’t even call it spotting. Here’s another thing.. it started a day after I had sex..unprotected. I’m not on birth control but I have been stressed lately so maybe that’s it? Just wanna know if I should be alarmed. I’m scared to take a test I don’t want to get my hopes up.