Most sensitive HCG test

i know this is kinda silly because they say they all work the same but my doctor is starting me on progesterone to help regulate my cycle & advised for me to take a pregnancy test each month before i start it. & i dont plan to obsess over taking tests & focus more on "letting it be" for now, so i wanna have a good piece of mind with trusting the result on the test & taking the medicine as prescribed.... also has anyone ever gotten pregnant while "regulating their cycle using progesterone."

no hateful comments please.