I had a tick latched onto me this morning that i removed. now i see a black spot where the mouth was but i can't tell if it is part of the tick or just a blood mark, etc. also what is the chance of developing lyme disease?

There are a lot of factors which influence the risk of contracting lyme disease including the region of the country you live in and the amount of time the tick is attached. A good reference is the following: https://www.cdc.gov/lyme/index.html If there is a possibility of residual material in the wound, it would be best to be evaluated in person by a trained professional.