I took a pack of microgestin birth control and took a break for two weeks. is it ok to start up again? what are the effects?

Yes: Yes, you can start back up at anytime. It might throw off your cycle, depending on where you are at when you re-start the pills. You may not have a period for 3 1/2 weeks, or you could have some breakthrough bleeding. Regardless, there's no harm in doing so. As far as contraceptive efficacy is concerned, you need to take for at least 7 days to be protected. Good luck!