HELP! AM I 🤰?!?

Ok so I was having unprotected sex for like a Week & a half starting on the 13th . My apps got messed up so I was under the impression that I wasn’t gonna ovulate for like 2 more weeks . WELL IT WAS WRONG ! I was ovulating on the 14th when another round of unprotected happened 🤦🏽‍♀️ My period is supposed to be due Jan 8th.. But on the 26th , 12dpo , I started bleeding. (Started light pink & went brownish) I thought it was the start of my period but it was kinda dark . Like a dark brown color almost .. I put in a tampon not thinkin anything n went to sleep . Woke up & when I went to change it there was only a lil brownish blood on the top . I put on a pad & it’s been the same thing . I won’t fill a tamp or pad .. Is that implantation bleeding ? Should I test ? Should I wait ? If so how long should I wait ? My period still hasn’t came yet & it’s now 2 days late . But I still have lil cramps & feel like I’m on my period just without the blood . What were you guys EARLIEST 🤰 SYMPTOMS ?!?! Should I be on the look out for any telltale signs ? PLEASE HELP GUYS ! ANY INFO IS GREATLY APPRECIATED !!! Thanks Have a nice day