Getting nervous

Me & my SO messed around a couple weeks ago & I realized my period was late. I took a couple tests & they were both negative. Yesterday, I started my period, but shocking, it stopped the same day, today I spotted a bit. I've never had this happen. Normally my period starts light, and gets heavier throughout the week. We bought more tests tonight, but I'm not sure when would be the best time to take them, considering I'm still spotting. Thoughts?