Never seen a lesion change like this

I noticed what I thought was a small blood blister on my tummy last year. I thought it was odd to show up for no reason but it was small so I didn't pay any more attention to it. The last few months it started to change and grow a little bigger to about 4-5mm in these past 3 weeks or so it has made some odd changes that I can't seem to find anything else like it on the internet. It turned dark and seemed to fill with blood but not much. Then when it ruptured I hadn't noticed until I saw a few tiny spots of blood on my shirt. But it formed a bruise ring around it. It didn't really hurt but was a little sore. Over the weeks I took pictures of the changes it made and I still have no idea what is going on. I have an appointment on Tuesday and I'm hoping it's nothing. I do have a history of multiple bcc on my face. The top left corner picture is what it looked like when it first started to change. Bottom left is what it looks like now. Any thoughts?