PREGNANT OR SICK?

So me and my boyfriend are sexually active and we had a pregnancy scare about a week ago so I took a pregnancy test and it came out negative. Its been another week since then. My period was late so I took a test two days ago and it came out negative again. Then the same day I came down with the flu. My period is now 4 days late. Is the flu messing with my period or am I possibly pregnant?