Ladies,
I couldn't help but to set the record straight.
For all new pill users (first timers, and the ones getting back on it) you need to use a backup method for the first month.
Current users: If you miss pills, backup is needed for 7 days, if more than three pills are missed usually your period starts. Always consult your package insert (save just one and keep it someplace handy for reference, especially if you have different dosed pills, more than one color for the 21 active pills)
As for when a pill becomes effective... this means fully effective as in all benefits and possible side effects, is three months. This is know as the amount of time that it takes the pill to "capture your system." During this three month time frame it can take a while to notice the benefits (less cramps, lighter flow, etc) and to see how your body "really" responds to that specific type pf pill.
As for the pill and backup method, I have always used both. And my bf at the time asked why, while a year later I found out that he was cheating on me. So... you the only one who can protect yourself.
As for HPV, yes it is spread by skin to skin contact. So foreplay can put someone at risk for tranmission. Condoms do help, but they don't cover ALL of the genitals.
Sorry for the long post but I work for the health dept as a sex ed teacher, so anytime there are question, I'll be happy to add input or answer