just a minor question

im pretty sure most girls know what a period is-. as I said in my last question thingy my parents forced me to get a girl friend- still don't know why yet-. well uh when i started- i saw some blood.. which kind of made me think to myself: "hold the fuck up.., this isn't her first time.. so she must be on her period-." having said that- as most of you know. that would be the first time i did that with a female. so i stopped and asked her if she even knew she was on her cycle- she said this word for word- "Yea, so what? its natural." which stunned me- and absolutely disgusted me-. because she was starting to stink- because she most likely didn't wash up- or she just needed to like go wash up again- so that i know im not just getting blood on my dick to where i can get an infection or an std- even tho i had a condom on still made me think before hand-. im honestly kind of mad and concerned for myself and my body near her sometimes-

and i just wanted to know if it IS natural to have sexual intercourse when your on your period-.?