It's been bout 41 days since the first day of my last period, could I be pregnant?

ok so the first day of my last period was June 16, 2010, today is July 27, 2010. I've bn having unprotected ((we have used the "pull out" method but lately he just finishes in me! (sorry didn't knw how else to put it) I've taken about 4 home pregnancy test and they come out NEGATIVE!! :( my period is usually irregular but this has been too long. Any suggestions? I've had some symptoms but idk if they are juz in my head or what!