Hi there,
I'm sharing an article that I know you've seen before but will highlight the parts related to your question.
Combined Oral Contraceptives (The Pill)
To use the combination pill properly, you need to take one pill every day, ideally around the same time of day every day. It's also important to take your pills in order with most brands (monophasic types are an exception). If you don't take it at exactly the same time -- but still take it on the day you're supposed to -- that won't make your pills ineffective: it's just a safer bet to take it around the same time to keep you in the habit to reduce the risk of you spacing out a pill on any given day. As well, with a medication like the pill that's all about rewiring a very specific process in your body that changes daily, taking it as close to the same time each day as you can helps to be sure your hormonal levels are as regulated as possible. If you want to be as close as you can to a perfect-use effectiveness rate, you'll want to try and take your pills within the same three-hour window each day.
With combined pills, you have a 12-hour grace period before a pill is late, and a 24-hour period before you are considered to have missed a pill. So, if you normally take your pill at 3:00 PM, and one day took it at 6:30, no need for worries.
When you first start the pill, when it will be fully effective depends both on when you start it, as well as your own body chemistry. For most people who start the pill either on the first day of their period or the first Sunday after a period, any brand of combination pill will likely be effective after seven days of use, but here at Scarleteen, as many other credible sources suggest, we advise users to give their pills one full cycle before going without a backup to play it safe.
If you ever do miss a pill, be sure to follow the instructions in your patient information and make it up as soon as you know you have missed it. If three or more pills in a pack have been missed or taken late, emergency contraception is advised.
For detailed instructions on how to use your particular combination pill, read and refer to the patient information insert that comes with your pill packs.
There is no perfect way to know how the sequence of your pill taking will impact effectiveness and how your withdrawl bleed will be impacted. Everyone's body is different. There is a possibility that your withdrawl bleed will be more irregular this month or the coming month.
If you are actively engaging in penetrative sex and are trying to avoid pregnancy make sure you use additional contraceptives (condoms). As the article indicates, it also may be advised to take emergency contraception if needed. (Do note that taking emergency contraception will impact your menstration cycle/bleeds). Generally, the pill will be back to its full effectiveness after 7 consistent days of taking the pill. Additionally, in the future, its good practice to take the pill as soon as you have realized you missed it. Meaning, you don't have to wait until the next day.
This chart by the CDC may be helpful:
https://www.cdc.gov/reproductivehealth/ ... ag508.pdf
I would advise you look into the specifics of the pill you take based on the patient information and if you still have further questions, I would advise reaching out to your medical practitioner.