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 <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">period app</a> 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 .