Advice please

Hello, I don’t usually like to post on this app because it’s a lot of work and rarely ever does someone answer. So please if you’re reading this, bare with me and give your best input. I had a tonsillectomy 1/9, my period was due 1/14. Guessing since they continued with my procedure, the test was negative. My period has arrived or so I think, i have had the same tampon in for 6 hours. I put the tampon in because when I wiped I had brown discharge. When I took out the tampon and saw that there was rarely anything I left it out. It’s now been 3 hours and there is nothing leaking, just a little brown when I push the toilet paper in the opening. I guess I’m wanting to know if the surgery could’ve made my period light or if it could be early pregnancy bleeding. I tested and this is also the result. Thank you ladies. Side note: I am so nauseous, all the time. I dont believe I have any other symptoms. I will test again if it doesn’t get heavier.