I had protected sex using condoms on 13 or 14th of December, I had my period on the 1st of December, I have missed my period which was supposed to be on the 1st of Jan but now its the 12th and I still havent had my period (I have to note that I travelled a long journey by train on the 30th Dec to a different country and I was also very sick, had cold), now my question is I am worried I might be pregnant? I have taken pregnancy test strips four times they all were negative...also I have no early symptoms of pregnancy, I have been eating a lot (that could be from stress)...my period has been regular for the past few months however there were times I was irregular...