low estrogen

Sarah • I`m 31, happily married SAHM to our beautiful daughters 30w preemie now 9y/o and after seven years of fighting infertility our now 2y/o currently expecting babe #3 August 2022 💕
Anyone know of any naural ways to boost my estrogen?? My OB has done my bloodwork on cd16 for three cycles of clomid now and said my estogen is too low each time... just confused because if I ovulate later its not going to show an estrogen spike cd16 it would show later.. Im so confused and worried my OB is just brushing me off. 
Also is there any reason my OB is insisting we do a cd 16 estradiol blood draw with my cycles instead of doing a cd21 progesterone blood draw?!?