plz help!!!! CAUTION TMI

before my doctor put me on my diet pills we didn't use protection but after we did. it was the middle of my ovulation that in was put on diet pills by my doctor and birth control but can't start the birth control unroll after my period. I'm suspose to start tomorrow and the last two days I've been cramping today I noticed some spotting and then some bright red with white creamy stuff in it when I wipe and now its like dryed blood what's going on could I have gotten pregnant before I started my diet pills or could I just be starting my period. I've never had this happen I usually just start and that's it . we were ttc baby number two but doctor said to wait till I loose weight so we agreed after 6 months of trying. can someone plz help