early ovulation due to missed birth control pills?

Hello. I am 21 years old and have been on ortho tri-cyclen for 2 years now. This past month, my period ended on July 30. I was not very good about taking my pills, I took a few of them more than 14 hours late. I had sex without condoms 3 times during the week after my period, but have not had sex since then. Is it possible that I could have ovulated early, as a result of not taking my pills responsibly? I know ovulation generally occurs mid-cycle, but since I am on birth control, doesn't that prevent ovulation from occuring? Could that mean that I could ovulate at any time in my cycle as a result of missing pills?

Since then, I have been feeling a little queasy and have felt 2 sharp pains in my breasts. These feelings began around the 12th of August. Also, i have felt a tightening/pulling sensation in my stomach several times and a few sharp pains which were very brief. I also had light spotting which lasted for two days on the 12th and 13th August, which would have been about 10-11 days after the last time I had sex. Could this be implantation bleeding? I also had back pains around this time, which could have been due to something unrelated, but I don't really know.
My period is not due until August 23rd...is it too early to take a pregnancy test even if I might have ovulated earlier than normal? Thank you very much.