confused about spotting?

Mikaela
Hello I've been taking sprinted birth control for about 5 months now and I haven't had any issues except for nausea in the morning. This ovulation period I have been spotting a lot. I got worried so I took a pregnancy test and it came out negative. Im supposed to get my full blown period in two days but I've had medium to light to heavy spotting for two weeks.. What's happening to my body