Help😬

So My period is 6days late but I took a pregnancy test this morning & it was negative. Is this something I should talk to my doctor about? I’m just not sure why it is late and what Is wrong. Or could I be pregnant but it’s just not showing? That may be a stupid question but my mom always told me that she was pregnant for 4months & her period never stopped until she was 5months & the test also came out negative. I have just never been this late in my life. As far as I’m feeling I haven’t had one sign of a period, not even sore breasts. The only thing I feel different is honestly it feels like bubbles in the very bottom of my stomach & it tickles but honestly when I talked to my bf about it he laughed at me & said I had gas🤦🏼‍♀️😅.