I had unprotected sex a week after my period ended (jan 29) , we used the withdrawal method, i took two pregnancy test yesterday and both came out negative but my period still hasnt come. it has been 25 days since sex could i be pregnant still?

Tests are accurate: Home pregnancy tests are very accurate and not affected by foods, herbs, common illnesses, sexually transmitted diseases, or medications. A correctly done urine test gives a reliable result 3 weeks after sex (3 weeks after when conception might have happened) 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.