Help!!!! Advice is needed

Okay ladies! So ive been on birth control now for about almost 4 months now. When i first started it i spotted for like a week n a half. Well now ive been spotting for almost 2 weeks and its not brite red its brown/pinkish. Well we had a oopsies with out pertection but used the pull out method. Honestly i was fine and not thinking pregnancy until my best friend put it in my head so last week i took a test it was a big fat negative. Thinking about switching bc i tried calling my obgyn to talk about options.