You can start conceiving from your first period.
It's possible that changing birth control pills will change the timing of your next period.
The first day of your period, with or without the pill, is the first day of bleeding.
You start counting on the first day of your period.
not necessarily your period could be changing when it is going to start so it bleeds close to your last period.
You may not have your period every month when you first start. This is because your periods will be irregular.
Are you wondering if you can get pregnant without having had your first period? Well, yes you can. If you're having unprotected sex when your first menstrual cycle is starting, then you can get pregnant witout having had a period first. That'd be unsuitably early to start having sex, and terribly early to become pregnant.
Yes; if you start birth control on the first day of your period, you'll have immediate protection.
You don't make it start genius.
It depends on your genetics. Most girls start between 11 and 15, there's really no cause for concern until you've reached your 16th Birthday without starting your period.
Check the package for specific information, but generally the pill should be started on the first Sunday after you START your period.
If you don't want your period this weekend so you are changing from Loesterin to Micrrnir and you stop your pills on a Saturday, you will likely start your period within 72 hours. Depending on how long your period is, you may not be done with your period by Thursday.