Period concern

Paige • Mommy to a Princess 👑TTC #2 with hubby ✨
December and January my periods came a couple days early than expected. Never on the same date. I'm usually used to my period starting every month on the same day but it's not happening like that. Well once again this month my period started a few days early, but it's like not even a period its just like a smudge of bloody mucus on a tampon. I'm used to heavy periods that require me to wear a pad and a tampon and sometimes more than one pad ! This period is strangely light and brownish and more like spotting. I also took a pregnancy test a few days ago and got a positive. (I have the picture) so I freaked out and immediately the bed day seen a doctor and had a urine and blood test done both negative and I even seen them. I even did a home test again to make sure and for some reason that positive quickly turned back to a negative. It's weird and my cycle is so weird. OBGYN doesn't think nothing of it. What's going on ?