I'm 28 Yr F. I Smacked A Mosquito Then I

I'm 28 yr f. I smacked a mosquito then I had a burNing sensation and hard knot an it hurt to put pressure on my leg. I rubbed it out now it's a huge green bruise. Since then the vein is traveling up my leg an thigh causing 2 more hard knots an bruises in different areas? Is it blood clot forming or anythig serious? The leg hurts when I stand up the pressure on it.