Help!

Katie
So I was suppose to start my period yesterday. I had some spotting and minimal cramping in AM but am on Vaca and going to the beach so popped in a tampon took some pain reliever to not ruin my day. Took out 2 tampons with hardly anything just brown spotting. I didn't have anything in all night and have had no spotting or cramping. Took a 25 mui test this AM which was negative. It was second morning urine and there wasn't much of it. I don't feel any period signs or pregnancy signs minus some slight one sided cramping that lasts about 2 seconds and vivid dreams. Any insight??