I met this guy on net few months back .One day I told him I'm nt well, he asks ,"r u having period?" ..is this normal to ask question like this to women ...we just talk on usual topics.

it really depends on ur age...if ure old and mature enough....say 16+ then it shdnt really matter.....

I sometimes make comments like that to my girlfriends but as a joke.. it's not a creepy thing to ask at all.. a creepy thing to ask would be like bra size and underwear and stuff like that.. another joke I use that is similar is, are you pregnant or something.. so i think he's a normal dude, so far.. be sure to tell him that you did get weirded out by it but that it's not a big deal.. just so he can restrain himself a little and not get too comfortable with you.

I do not think this is a weird question to ask.
He wanted to know what was wrong with you.