I Have Been On Microgynon 30 For About 9 Months,

I have been on microgynon 30 for about 9 months, and it has worked fine. Last month I didn't take it because I forgot for the first week, I had my period and started to take it again this month. I am sexually active, and usually use a form of protection. I have been taking the microgynon for about 2 weeks this month, and I am not due to start my period for another week and a half, but yesterday I bled lightly , at first it was brown/ red but now it is completely red. Do you know if this is to do with the pill or possible pregnancy?