I was suppose to have my period on 22nd June of this month bt still no period and I have taken 3 tests which are negative,is it possible to become pregnant?

Do you man is it possible you ARE pregnant ? Since the question "is it possible to become pregnant" would mean you are not currently and will become in the future.

False negative readings are common, are you doing this first thing in the morning with the first urine of the day ? If not try that. Or wait to see if you get your next period, if not, see your doctor.