Heavy period and birth control pills

Keri
So I started this birth control called Orsythia on March 13th 2017. It's my first time ever using the pill so my body has yet to get used to it. I followed the directions and started it within the first 24 hours of my next period (I got it on the 12th in the evening but started the pills on the 13th since I wanted to take them in the morning). I've had killer headaches and sometimes intense nausea. I'm on my 7th day (tomorrow should be my last day) but it's heavier than usual. Around this time before I just had spotting during my last two days so I'm a little worried. I've had mild cramping this whole week and during the 2nd and 3rd day I bled through one tampon within 2 hours of changing it then it happened again two hours later after I changed the last one. I've never bled this heavily before so I'm wondering is it because my body is just trying to get used to the pills?