Will Brown Vaginal Discharge Convert Into A Period While On Contraceptive Pills?

I missed a birth control pill last Friday and doubled up taking two on Saturday. I've been taking them all on time every day besides that one Friday that I missed. I've been on birth control for almost 6 years now. On Wednesday I started experiencing some very light brown discharge on my underwear and when I wipe. I was adviced to just keep taking the pill and it will go away, so I have been doing that. It got lighter over the next two days but then the light brown discharge got darker. I'm seeing my boyfriend next week whom I haven't seen in 4 months and I wanted to have a special weekend with him. Will the brown discharge go away or turn into an actual period while I'm still on the pill or is it still okay to have sex with brown discharge?