After 7 birth control pills, can I change them to a patch?

You did not give the name of the contraceptive patches. I answer below on the basis of the summary of product characteristics of Evra as it looks like in the case of the sample product with patches. Of course, you should make sure that in the case of your patches it is also recommended to do so. EVRA should be started on the first day of withdrawal bleeding. If there is no withdrawal bleeding within five days of taking the last active (hormone-containing) oral contraceptive pill, then pregnancy must be ruled out before starting EVRA. The manufacturer of exemplary Evra patches (because I do not know which one you will use) does not foresee such a scenario as your case, so in my opinion the best solution (since you do not have tablets) is to wait until the bleeding occurs and only start using the patches. However, due to the fact that you have stopped the tablets appropriately during the cycle - bleeding may occur a little earlier or later. I leave further information from the manufacturer of Evra patches: When the use of the patch begins after the first day of withdrawal bleeding, a non-hormonal method of contraception should be used simultaneously during the first 7 days. If it is more than 7 days after taking the last active tablet of the oral contraceptive, a woman may experience ovulation and therefore she should be advised to see a doctor before starting evra. If sexual intercourse occurs during a prolonged break of more than 7 days from the oral contraceptive pill, the possibility of becoming pregnant should be considered.