Today is August 4th and I still don't have a period. This is my first month taking these pills seeing that I switched from Ortho tri cyclen lo because I could not take a pill containing estrogen. I have not skipped any pills, however, I was put on Antibiotics for possible lyme disease 2 weeks ago. Also, I was not sexually active while taking the antibiotics because of their reduced effectiveness of the pill. Could the antibiotics be the reason I am not getting a period?

It could very well be the switch in the birth control... if you are concerned you can try a pregnancy test.. but birth control has different effects on different people... I was on the ring for a little while and never got a period even though I was supposed to..