Newly married, was curious on how well condoms prevent pregnancy? am not on other birth control due to bad reactions in the past?

If used correctly , judiciously, and responsibly, they can be very effective. However, there can be occasionally breakage and slippage. So they are not 100% effective.

When used correctly, condoms are highly effective at preventing pregnancy. According to Planned Parenthood, condoms have a failure rate of 2% when used correctly and consistently. However, with typical use, the failure rate increases to 18%. This means that out of 100 couples who use condoms as their primary form of birth control for a year, 2 will become pregnant.