Wednesday, January 27, 2010

The Logic Behind Sunday Start

Dear Dr. Kate,

I recently began taking Ortho-Tri Cyclen again for a variety of reasons and I've always been a Sunday starter, so I wanted to stick with that routine. I began my period on a Friday and, like clockwork, started taking my pills on Sunday morning bright and early. I know I am suppose to use a back up method for the first seven days if I am a Sunday starter. Here's my question...why is this? I understand if I woman starts on Monday and is a Sunday starter that she has the potential to ovulate during the first week of the pills, especially if her follicular phase is short, but if I start on Friday and begin my pill pack on Sunday, what are my odds of ovulating in the first seven days?


Sunday Starter

Dear Sunday Starter,

The advice about when to start the pill and for how long to use back-up has more to do with simplicity than science. There's no magic to beginning the pill on Sunday - it's been long thought by doctors that it's easier to start the pill pack with the start of the week. It's fine if Sunday works for you - it gives you the whole weekend to get your pills refilled, and you may be more likely to be home on a Sunday night to take them. But in general, you can begin your pill any day you want - even if you're not on your period ("Quick Start").

The issue of back-up birth control has two parts. If you begin your pills within 5 days (some say a week, I'm more cautious) of the start of your period, you're protected. So if your period begins on a Friday, you're right that if you begin your new pill pack on Sunday, you don't need back-up that cycle. But if you begin your pills later than 5 days after bleeding begins...or in the middle of the'll need condoms for a full 7 days after. Because this rule can get complicated, many doctors simplify it to "always use condoms for the first week of the pack." In theory, if it's not really a period when you start your pack (you just think it is), then you'd be at risk of ovulating, and would need the condom back-up. But if your bleeding looks and acts like a period, your chances of ovulating that week are very low.

Best of health,
Dr. Kate

Photo credit: Vincent Caplier


hopscotched said...

Dear Dr. Kate,

I am so confused right now! I can't understand what you're talking about - starting on the pill for the first time in a while or starting a new pack (as in every month). Does this mean that there's a week in every month that I need to be using a condom?

Dr. Kate said...

Hopscotched, I'm sorry for the confusion. When you begin the pill for the first time not on your period, you need to use condoms for a week. But as a regular user, who uses the pills correctly, and doesn't start a pack late, you don't need condoms for pregnancy prevention. Of course, they're still your best bet for STI prevention, though.