Spotting on the pill.

Jay
So I've been on the pill for about 3 months now, I skipped my last period as I was going to be away for a weekend camping and didn't feel comfortable about not being able to have a shower for 3 days while on my period. 
I consulted my doctor, and she said it was fine. 
That was 3 weeks ago, but for the last two weeks I have been experiencing spotting every day. Just little bit of blood, sometimes it's a really light pink, I have no idea what's going on, it's been going on for two weeks straight, usually if I am spotting it's only for a day or two, not weeks. 
Any idea what it is?!