TTC nor surw what this was?! Idk

Ok so I'm only 6 DPO, I have very sore breasts back is killing me. On my 5th DPO that night I had went to pee, a dark red like cyst came out idk really what it was. I have not started bleeding I don't hurt🤔 I have no idea what this could have been.... I read up on alot of possible things it could be but I'm not sure. Uterus shedding, corous luteum, idk guys... I have also got a picture it was form of a ball like cyst as I said earlier until i messed around with it. Im suppose to start my period in a week also. Should i worry or no.