How long did you wait before you had sex with SO?

So I’m talking to this guy and I was thinking, if I get into a relationship with him (which at this point is really probable), how long am I supposed to wait before I have sex with him? I am a virgin and don’t think I am ready to have sex anytime soon. I want to wait at least 4-6 months after we are serious before I have sex... is that unrealistic or rude? Idk. I don’t wanna lose him just I won’t have sex with him.