I've been on birth control for 4 years and I switched brands about 1 1/2 - 2 months ago. I also haven't had sex in 6 months and I've recently started having sex 2-3 times a day, every other day (military relationship, lol). I've been experiencing light brown and red spotting for a couple of days. Could this be because of the birth control switch or the sex or both? I'm 17, have been sexually active for 2+ years if that helps. No chance of STD, partner and myself have only been with each other. Thank you!