Lab ranges vary so that looking at another lab's ranges, one can see levels are much higher at ovulation.
http://www.ilexmedical.com/files/PDF/Estradiol_ARC.pdf"Normal estradiol levels are lowest at menses and into the early follicular phase (25-75 pg/mL) and then rise in the late follicular phase to
a peak of 200-600 pg/mL just before the LH surge, which is normally followed immediately by ovulation. As LH peaks, estradiol begins to decrease before rising again during the luteal phase (100-300 pg/mL)."
http://www.pathology.uci.edu/psm_public/FormView.aspx?descid=461&alpha=&opt=1&ansFollicular: 23 – 145 pg/mL
Midcycle: 112 –
443 pg/mLLuteal: 48 – 241 pg/mL
Maturitas. 2005 Apr 11;50(4):266-74."Normal concentrations obtained via a fluorometric method, vary with the phase of the woman's menstrual cycle. During the follicular phase, they range from 35 to 184 pg/mL; during the ovulatory phase, from 191 to
540 pg/mL; and during the luteal phase, from 40 to 228 pg/mL; at menopause, the 17β-estradiol level decreases to about 35 pg/mL. »
Am J Med. 1995 Aug;99(2):119-22."normal postmenopausal plasma concentration less than 200 pmol/L (less than 54 pg/ml); normal premenopausal physiologic ranges: luteal 368 to 1,100 pmol/L (100 – 300 pg/ml), midcycle 785 to 1,840 pmol/L (214 –
501 pg/ml), follicular 74 to 368 pmol/L (20 – 100 pg/ml) for estradiol"
http://www.specialtylabs.com/clients/outreach/web/site/details.asp?tid=44312&cid=301&keywordFemale normal by day of the week relative to LH peak:
Follicular: 21 - 251 pg/mL
Mid Cycle: 38 -
649 pg/mL Luteal: 21 - 312 pg/mL
The right estradiol levels for a person cannot be determined in advance. There are so many factors to account for, like genetic predisposition (and sensitivity), metabolism, etc. Estradiol levels also fluctuate in time.