Blood clot from sunburn, should i be concerned?

Purpura?: I'm a little confused by your question, as I have never seen a sunburn cause a blood clot. I believe you may be describing purpura, or a dark purple plaque that results from bleeding in the skin. If that is the case, you don't need to be worried, but you should be more careful in protecting your skin since blistering sunburns increase your risk for melanoma. I hope this is helpful.