Virginity

Im 21. I'm seeing a guy and I like him a lot but I'm really hesitant on if I want to have sex with him. I want to sometimes. But sometimes I just get lost in thought because I have this paranoia about becoming pregnant and I just don't know what to do. He's been patient and what not but for me to give my virginity is a big deal for me. Mentally I think it would really fuck with me because I'll get really attached to him ans I need to focus on school. I'm terrified I'm gonna get pregnant, esp since my period is a bit irregular. Yes there's condoms but I just can't. I'm really scared of getting pregnant. Thoughts anyone??