I was wondering if anyone has experience with tick bites and possible Lyme disease?

Last week I had this mosquito bite (at least that's what I think/thought it was), and after a few days it went from average mosquito bite to a big red circle, like an allergic reaction or something. Then 4 or 5 days ago the center of the red spot became a red-purple bruise (a bit like this but with less defined edges, it did look more like your general bruise: https://edc2.healthtap.com/ht-stagin...peg?1386641491 ) and I started to put some cortisone creme on it. I went to see a a doctor because I became worried that it might be a tick bite (even though I didn't see one, and initially it looked and felt like a normal mosquito bite) and it didn't really hurt like a bruise does when you push you finger on it. The doctor said that it looks like a bruise and that she didn't think it was a tick bite since it doesn't have that typical white and red circle around it. She told me to keep putting the cortisone creme on it and prescribed another creme against bruises. She said keep an eye on it and see if it gets better or not.

Today the bruise in the middle of the red spot is mostly gone and is more pale and reddish again like the rest of the red spot. But nevertheless the red spot is still there (a bit like this but then redder: http://www.skinsight.com/images/dx/w...e_44250_lg.jpg ). The bite itself isn't visible anymore like it was initially. It's also not swollen or anything like I've had with reaction to a mosquito bite once. I'm kind of worried that it still might be a tick bite or something since the redness doesn't really go away and I read that a tick bite doesn't always look like the typical bite with the circle around it I'm going to see a doctor again next week if it doesn't go away, but I'm scared that if it goes away and it was a tick bite anyway that I might get Lyme disease.