Do antibiotics mess with your AF cycle?

[zephyr]

GRRRRR. I am asking this because my AF is a WEEK late and it's never *that* late. And I've been on antibiotics for the past month or so, first on penicillin then on clindamycin. I finally finished my round of them about 1.5 weeks ago. So not really sure what to expect because I've never been on them before. And I'm 99% sure I'm not pregnant but I did go out today and bought some pregnancy tests that aren't from the Dollar Store because those seem to not work for me. Any BTDT advice would be so appreciated since we were not planning on getting pregnant yet at this time. :confused:

[elephantmeg]

they do invalidate many forms of BCP but I've never heard of them affecting your cycle. However being sick can.

[jal]

Ditto on what Margaret said.

There's all sorts of things (illness, stress, etc) that can easily cause your body to decide to put off ovulation (and hence delay AF).

[mommylamb]

You might want to save one of those pregnancy tests for next week just in case you are pregnant and it's not showing up yet.

[lisams]

Being sick can for sure delay ovulation. It's happened to me a few times. And like the PP mentioned, some antibiotics can interfere with the effectiveness of birth control pills.

Hope everything turns out the way you want it and you have some answers soon!