I Am 7 Days Post Gallbladder Removal Surgery. I Have

I am 7 days post gallbladder removal surgery. I have had light vaginal bleeding since day 3. I am not supposed to be on my period anytime soon as it ended 3 days prior to surgery. My post op check up is tomorrow but tonight I noticed the bleeding was a little heavier. What would cause this? My periods are normally regular. I am 28 and otherwise healthy.