no chance of being pregnant take her to the gp and see what the doctor says
When starting a new birth control often times you are not regular right away and many women will spot/bleed (called breakthrough bleeding) when it's not there time of the month. With most (from what I read and personal experience), after 3 months of being on birth control they should be back to normal or close to normal.
Also, some women bleed around ovulation time, since it's 2 weeks after her period that's a possibility too, I've never had it so I'm not sure how long it typically lasts.
My guess it it's just her body getting used to being on the birth control, but if it continues for more than a few months she might want to at least mention it to her dr. Also, if you know what she's taking you can google that and see if one of the side effects is breakthrough bleeding or spotting. I've heard breakthrough bleeding is very common with IUD's, and when I was on the pill I had it for the first 2-3 months I started taking it.