Period while on BC Pills. Please help?

Elizabeth

Okay, so I'm on birth control pills and I only take the active pills (as prescribed by my dr of course) so I don't get my period. I haven't gotten it in around 3 months (since I started taking them) but a few days ago I started getting cramps like I was going to get my period, and then instead of the bright red blood like I got before, it's darker brown and barely any flow- I really only notice it when I go to the bathroom and wipe after; like it's enough to be more than just discharge, but not enough to get on my underwear and whatnot. Anyway, I was getting kinda worried and I can't make a dr appointment, so I did a little research. Basically what I found was that if you haven't gotten you period in a few months, it's likely just old blood. I'd like other opinions on it though. Has this happened to anyone else before? Thanks in advance!

Update: normal blood is a thing now! No longer as worried about it as I was. Thanks for the help though guys! Much appreciated!