I recently been having boils in my armpits and thighs. I'm not sure whether its caused by the aspirin I'm now taking as blood thinners. Can anyone help me?

I can't really say for sure what causes them, but I can tell you some things that may help prevent them. You can exfoliate your skin at least twice a week. This removes the dead skin that holds bacteria underneath your skin. Also, after showering or bathing wipe your body down with witch hazel. This helps the pores close before any bacteria can get into your pores. Hope this helps.
There is a product called boil ease that you can buy and the drug store, but this only helps once you have them, and, at least where I live, it is very had to get.