I am not sure how to ask this. Do you know if you can conceive when you have intercourse a day before expected cycle is to start?

Probably not. You can only get pregnant when you have an egg waiting for the sperm. You only release one egg a month and this is usually 14 days before the start of AF. And the egg only lives for 12 - 36 hours.

So the chances that you can get pregnant if you BD the day before AF is due is very very very slim.

Hope this helps.