Light pink spotting ?!?!

I'm not due for my period until the 17th . Which is in 5 days ... however today I've been cramping on and off like I am on my period . I haven't cramped anymore since 3pm today ... and all day I've had this bleeding .

My period blood is usually a bright cherry red . However this is pink and I'm basically spotting . . I haven't had a need for a pad or for a panty liner . I would've never even known I was bleeding if I didn't see a tiny bit this morning on my paper when I went to pee . And now it's coming out as a little brown almost as if it's now turning old and coming out with the pink blood ...

We're not actively trying and when my period app says I'm ovulating we don't do anything .

I had my period last month like normal .

Has anyone else experienced this ???

Also we did have sex last night .