My estradiol level is low. Will taking DHEA help in increasing the same?

Hello doctor,

I had a miscarriage two months ago resulting in a D and C at 10 weeks.I am now pregnant (4 weeks and 3 days) and taking 400 mg Progesterone suppositories once per day due to low progesterone levels both in the last pregnancy and in the weeks leading up to the confirmation of this pregnancy. However, my doctor has told me that my estradiol is very low, and that is concerning me. My results so far:

14 DPO

hCG 69 U/L

Progesterone 77 nmol/L

Estradiol 220 pmol/L.

Two days later:

16DPO (yesterday),

hCG 129 U/L,

Progesterone 75 nmol/L,

Estradiol 239 pmol/L.

Is my pregnancy doomed because of my very low estradiol? I was hoping my doctor would prescribe estrogen medication but he does not seem to think that would be an option. Why would he decide that? Do you think estrogen supplementation would help? Instead he is having me take 25 mg daily of DHEA. Do you think this will help and is it safe to take in pregnancy? Will eating foods high in phytoestrogens e.g. soy help increase my estradiol? Also, do you think my low Hcg levels are a bad sign? At 12 DPO they were 15 U/L so they increased rapidly to 69 U/L on day 14 but then slowed a bit to get to 129 U/L on day 16. I am due for another blood test tomorrow. I really do not want to lose this pregnancy, but these low numbers are making me worry.

Thank you doctor,

The reference ranges I have read say that estradiol levels in the first trimester are normal between 188 to 2400 pmol/mL (rather than pmol/L). If my levels are 239 pmol/L (not per ml) are not my levels concerningly low?