I was taking nur-isterate injection for 4 years and i was expected to take another shot on the 21 july but i didn't and i had an unprotected sex on 19 august, am i pregnant?

Maybe/not, take a pregnancy test. For full effectiveness the injections should be taken on schedule. However, many who decide to come off birth control and try for pregnancy find it can take quite some time before full fertility returns. If concerned about pregnancy a first morning urine should test positive at 2-3 weeks after exposure.

Conception occurs within day or so of the sex. It takes about 3 weeks for the embryo to make enough HCG for a positive pregnancy test. Blood test may be done a day after a missed period. Home pregnancy tests should be done 4-5 days after the missed period. If the result is negative repeat the test in 4-5 days. Use first morning urine and follow instructions for the test carefully.