There was some precum on his hand and later he touched me, so now I am anxious. We did not have proper sex but my mind is stuck on this. Can pregnancy happen like that?
Relax, this wont cause pregnancy. On the hand it's not a real risk at all. If you're worried about these things in general, just learn about contraception properly so you stop stressing over every little thing.
Take a deep breath, this is not something that leads to pregnancy. It needs direct contact inside the body. You can relax on this one. If doubts keep bothering you, a quick doctor chat will settle your mind.
The risk here is basically negligible. Once it's on the hand and exposed to air, sperm dies very quickly. If you're anxious about pregnancy in general though, talking to a gynac about proper contraception will give you real peace of mind.
Pregnancy from precum on the hand is extremely unlikely. Sperm doesnt survive long outside the body or on the skin, so just touching isnt going to cause it. For pregnancy it really needs to enter the vagina directly.