Period late issue. Alcohol and smoke?

Hi, my date of my cycle was 17th and in March I didn't get my periods. I went on a trip with my partner on 20th and didn't receive periods by then. I consumed alcohol and smoke there in the trip too. Also had an unprotected intercourse. He didn't ejaculate inside but we had sex repeatedly after one session without washing the genitals. We came back on 25th March. Since then there was no sign of periods. I was afraid of been pregnant so did a test on 27 or 28th march.. and the results was negative both the times. Since yesterday I have cough n cold and lil fever today. Is there a chance I can be pregnant as results were negative then or should I wait for my periods to come n consider the delay of periods to be unhealthy food, alcohol and smoke?