Is a progesterone level of 2.4 ng/ml on day 3 of my period (light) a normal level?

Sure: That is normal but not really applicable. One expects a low Progesterone in the first half of the cycle. If you are testing for ovulation Progesterone is usually checked around Day 21.

Variable: The progesterone levels vary according to the phase in a menstrual cyle. A mid-cycle woman may have levels in the low 20s. First trimester it can be up to 90. A 2.4 ng/ml migh mean the patient has ovulated and the level is dropping