I stupidly had unprotected sex on Saturday night. My period was due last Wednesday but never came. My period is here today though (unless I am just randomly bleeding), does this mean that I'm not pregnant? Thanks.

If you had sex on Saturday the 18th of September the sperm hasn't even had time to reach the egg yet.

You now have to wait until you miss a period to test to see if you are pregnant.

Or did you have sex a week ago, Saturday Sept 11?