Hi, I am 21 year old.we are trying for baby. My menses date is 17 and I din get bleeding till nw.4 days late, am I pregnant? Can we have sex these days?

If you got your period the chances of you being pregnant are slim.
You should think about buying an ovulation test, to see when the best days are to try and get pregnant.
Try looking up positions for trying to get pregnant,
I no misanary is one and I sure there are many more...
Good luck ayeshan!