16 and might be pregnant?

Okay so I'm currently 16 I've only been 16 for five months me and my boyfriend have sex normally, the one time that we didn't use a condom my cousin had had sex that same day a week later we both took a pregnancy test and both showed up negative. Five weeks has passed and she just found out that she is pregnant six weeks now I'm worried that I might be pregnant to
*****update I'm not pregnant*****