No form of contraception is perfect, so the question becomes 'is it reliable enough for me?'
Used properly, condoms are very reliable. They're reliable enough for me, but I am not you.
If they are not reliable enough for you - how bad would a pregnancy or a scare be for you? - then a wide range of alternative or additional methods exist. They have different reliabilities, advantages and drawbacks, so talking to a specialist in contraception can be helpful.