Pregnant or Period?

Hey guys so my boyfriend and I have been safe and have had any issues for almost a year now. Im also on the pill and have been for atleast 7 years now.

I was supposed to get my period on Wednesday (the 19th) but I only had a little spot in my underwear that mornung and later that night. Since then its only been a little spotting. My period is normally regular the forst 2-3 days and then light till today (Sunday the 23rd) and then I'm off it. My stomach has been hurting and I have been really hot once in awhile. My low back has been giving me issues for atleast 2 weeks now but I didnt think anything of it. I have also been tired more recently. I've been so stressed as well.

I took a pregnancy test on the 19th but it came up negative. I plan on taking another a few days after the spotting is done but I don't know what else it could be.

Please any advice or suggestions??