Sporadic bites or red circles.

I have had what I have assumed are bites popping up on my legs mainly for the past 4 weeks. I assumed they were bites because they are small red marks. We have cleaned the house multiple times, washed the sheets constantly, examined the bed very closely and can't find one trace of a bed bug, I often wear mosquito repellant and have even taken to wearing socks/trousers constantly - yet these bumps still arise. So, now I'm thinking it is something else other than insect bites. Yesterday, a patch of about 9 flat, red, non itchy, circles the size of a small coin appeared on the back of my calf - this is often how the marks first appear, within 2 hours they'd disappeared completely, and overnight they have reappeared and 'morphed' into what looks like a more normal insect bite - smaller red marks with a whiter area around the outside. Still, they don't itch. Others I have had only itch at the very end when they seem to be finally disappearing for good/healing.