There are 2 painful, deep red-purple bumps on the ball of my foot near the smallest toe, and 1 on the inside arch toward the heel. what could it be?

Blisters to bug bite: It could be a lot of things, blisters, bug bites, foreign bodies, etc. Do you have a picture?

Need more info: Hard to say for sure without a complete history and examination. See the podiatrist! could be a bruise or a swollen vessel, but if there was no associated trauma, could have been a vessel that popped or a growth. Have it checked!

Are these: Sudden? Could be a bruise, a hyper pigmentation, blood under callous, wart and many other possibilities would see podiatrist.