I had unprotected sex on my last fertile day which was june 10th but on the 11th and 17th also. i was supposed to get my period on 24 but i didn't. could i be pregnant?

Sure: Can do a preg. test. A urine preg. test gives a reliable result 3 weeks after sex (3 weeks after when conception might have occurred), or 1 week after missing a period. If done sooner, a positive result is likely real, but a negative result may be due to testing too soon, and thus lead to a repeat test. If a woman gets her normal regular period, then she is not pregnant, and a test is not needed.