negative test shows positive days later?

i had some symptoms and random spotting a couple weeks ago. i took a test 3 days ago not thinking much of it i’m sure i wasn’t pregnant it showed negative but i didn’t actually wait much to see if anything appeared apart from the control line today i was emptying the bin when i saw it and it had two lines. now i’m wondering if it’s just a false positive or what? cause my period came today. i’m gonna make a doctors appointment anyway to talk about the spotting which lasted two days. but i’d like to know what others think first. thanks !