Definitely take a picture of it with a quarter next to it to give it size definition. You will want to keep this for your records just in case it is a tick bite. It's hard to tell you too, if it is indeed a tick bite without a picture. A "typical" bullseye rash, makes a bullseye shape....but there have been MANY tick bites that either do not have a rash at all, or have a rash that doesn't even look like a bullseye. I have a link in the "New To Lyme?...Start here
!" thread that has pictures of bullseye rashes if you want to take a look. Either way, keep an eye on it. My husband had a bite once that was hard and it turned out to be a spider bite. It got really infected and he had to have it drained, so keep an eye on it either way.