question: Hi, i am a singaporean. My last period started on the 10 december and ended on 15 december. My period are irregular. Am i possible to be pregnant if my boyfriend does not ejacualate inside me? The last time we had sex was on 10 december. He did not ejacualate inside me. Recently i have feel cramps but it had already stop. My breast are not really tender and my nipples did not change in colour. By the way does gastric problems delay period?