Condom protection rates are gonna be 97-99%, but that can go down if they aren't used or stored properly. Some basic tips...hehe, pun intended:
1. Store them at room temperature. If they are exposed to direct sunlight for prolonged periods of time, near a heating vent, or say in a car even on hot days, that'll affect it.
2. Pressure can damage the material. So keeping one in your wallet is actually a bad idea.
3. The expiration date matters. Check your container for the expiration dates of the condoms. If you have no way to prove they are still good, I'd avise just paying for a new box. Fifteen, twenty bucks depending on what you buy and wehre you are is way cheaper than a child.
4. Breaking during use, even if not at the tip, is gonna make things worse. So buy condoms that fit, roll them down and make sure there isn't any air trapped inside.
As for other ways to help matters:
1. Technically, precum can get a woman pregnant. It contains sperm, but the odds are incredibly low. That being said, even a 1% chance will yield tremendous consequences of you draw the proverbial short straw.
2. Her being on the pill helps with pregnancy, not STDs. But honestly? Outside a relationship, I never believe a girl who says she is on birth control pills, IUDs, or anything of that nature.
3. Her mouth can't get pregnant
