I agree with Gretchen sometimes it can take your body a while to get used to being off the pill. It took my sister in law like 6 months to finally get her periods back and on track, and sometimes they are still off a little. But you could be pregnant, I was put on Yaz after my miscarriage to regulate my cycle, and I got pregnant again on the pill, and normally my breasts are sore from ovulation to my period and the month I got pregnant my breasts didn't hurt until I was 6-7 weeks, I would give it a few more days and then test. With this pregnancy I didn't get a positive until I was 4 days late. Good luck, I hope you get the answer you want.
Sometimes when you stop taking birth control pills it takes your body a little time to regulate itself back to where it was before taking the pill. That may be what it is. If you miss your period for a considerable amount of time then it will be time to test for possible pregnancy. The only way to know is to test. Good luck!