I got off my birth control last month I bought another refill but only took the first week & had 2 periods last month but yesterday it didn't come on?

Irregular period. Any time you miss or stop your BCP midway in the pack you will get irregular bleeding. Make sure you practice safe sex until your next regular period and then restart you your pills with a new pack. Make sure you take them every day so you don't get pregnant and avoid the irregular bleeding issue. Good Luck.
Normal. You will bleed whenever you stop pills and if you do so after 2 weeks you can expect to have another period and so 2 periods in one month.The uterine lining then has to regrow so you will not be likely to have your next period on time.The bigger concern is that you also won't be protected against pregnancy so you should check a pregnancy test just to be sure and repeat it in 1 week if it is negati.