I take my pill everyday, no pregnancies, every cycle is on time. this month isn't, but i've had a bad cold the past 3 days. is this delaying my cycle?

Perhaps: Remember that when you are taking birth control pills the pills are in charge of your cycle not your body. It is not rare to skip a cycle when taking birth control pills. Continue to monitor over the next few months. If you are concerned about pregnancy you can always check a pregnancy test

Likely: The infection is likely what is causing your period to be off. However, even with a regular use of birth control pill there is a failure rate. If you are concerned the best thing to do would be to get a home pregnancy test.

Oral bc: no period: A bad cold will generally not affect your cycle, especially on bcp. Sometimes on long term oral bc therapy, the lining of the womb is so thin, that there is little to degenerate (bleed) when the "period" is supposed to happen. Just continue your oral bcp and your cycle will resume.