Tiny bloodsucking insect?

If you take a photo or even sketch a picture since you've examined it under 'scope, you can post it here, or post it on bugguide.net for identification. Your description (oval, but like a roly-poly) and its location and behavior sounds similar to a bedbug, but it's hard to even guess without seeing it. Sowbugs and pillbugs (roly-polies) do not bite humans. There are different kinds of bedbugs and ticks, and just because you are familiar with and ruled out one kind doesn't rule out all kinds. Also, a lot of arthropods look very different in early stages vs. later stages.