How soon is too soon??

So I did the “bd” pretty much all week except 2 days during my fertile window (Christmas eve until tomorrow but husband left this morning on a business trip) and as of yesterday I’m feeling pretty dizzy and light headed- I did the HSG test December 20th and I’m hoping it flushed my tubes out for some semen to stick , I know I sound crazy and my period isn’t due until around the 14th, is it possible my body is telling me something— how soon can a woman know she’s pregnant?