i am so confused

so i got what i think was my period at 13dpo , it came in TMI very very light with just some brown spotting on friday , saturday it was still brown with a little red but still very light and then stopped sunday morning. my period usually lasts about 5 days and aren't light like this at all. any ideas ? i feel like i'm grasping at strings here and i'm not sure what to think. i've never had a period like this , usually comes in a medium flow and it's quite heavy the first 2 days , then it slows down and on the 5th day i just spot brown on and off. this time my period was literally 2 days and a bit of the third day and it was pretty much just brown spotting with a little red on day 2. i didn't get any of my normal pms symptoms when it came and it was so light that i probably could have just worn a small panty liner all day and all night without needing to change it. i always told myself i wouldn't be the one who gets a period and refuses to believe it's her period but this time it's just plain weird. sorry for the rant , just looking for some advice