what kind of bug bite is this?

i have this bug bite and it’s getting worse. i initially thought it was a mosquito but now think it may be a spider bite??

thursday i wore shorts and sat on concrete steps while watching my boyfriends softball game and am assuming that’s when i got this.

friday i had a red circle on the back of my thigh but i didn’t feel it.

yesterday it got bigger and still very red so i’ve been keeping and eye on it

today it looks like a bruise that’s spread and the color has turned more purple. depending on how it looks tomorrow i may go to urgent care to have it looked at.

any ideas?

(again i didn’t feel it happen, it doesn’t itch, and isn’t painfulf)