Hi. My current cycle is 35 days. My last period was on April 02. I ve travelled a lot these past few weeks wherein I have to migrate from Philippines to Singapore. On May 09 to 13, I ve been sexually active for four times. Then until now, I have not yet had my period. I ve tried pregnancy test once and result is negative. Sometimes, I feel like having cramps but I think it is psychological only since I am so worried that I might be pregnant. Is it possible I am pregnant? How can I be sure and how to avoid it?