Have you guys heard about Early Pregnancy Factor? The last paragraph deals with us Clomid ladies specifically, but read the other paragraphs first, b/c they explain everything. From wikipedia:
Early pregnancy factor is tested for rosette inhibition assay. EPF is present in the maternal serum (blood plasma) shortly after fertilization; EPF is also present in cervical mucus and in amniotic fluid.
EPF may be detected in sheep within 72 hours of mating, in mice within 24 hours of mating, and in samples from media surrounding human embryos fertilized in vitro within 48 hours of fertilization (although another study failed to duplicate this finding for in vitro embryos). EPF has been detected as soon as within six hours of mating.
Because the rosette inhibition assay for EPF is indirect, substances that have similar effects may confound the test. Pig semen, like EPF, has been shown to inhibit rosette formation - the rosette inhibition test was positive for one day in sows mated with a vasectomized boar, but not in sows similarly stimulated without semen exposure. A number of studies in the years after the discovery of EPF were unable to reproduce the consistent detection of EPF in post-conception females, and the validity of the discovery experiments was questioned. However, progress in characterization of EPF has been made and its existence is well-accepted in the scientific community.
Early embryos are not believed to directly produce EPF. Rather, embryos are believed to produce some other chemical that induces the maternal system to create EPF. After implantation, EPF may be produced by the conceptus directly.
In humans, modern pregnancy tests detect human chorionic gonadotropin (hCG). hCG is not present until after implantation, which occurs six to twelve days after fertilization. In contrast, EPF is present within hours of fertilization. While several other pre-implantation signals have been identified, EPF is believed to be the earliest possible marker of pregnancy. The accuracy of EPF as a pregnancy test in humans has been found to be high by several studies.
Infertility and early pregnancy loss
EPF is useful when investigating embryo loss prior to implantation. One study in healthy human women seeking pregnancy detected fourteen pregnancies with EPF. Of these, six were lost within ten days of ovulation (43% rate of early conceptus loss).
Use of EPF has been proposed to distinguish infertility caused by failure to conceive versus infertility caused by failure to implant. EPF has also been proposed as a marker of viable pregnancy, more useful in distinguishing ectopic or other nonviable pregnancies than other chemical markers such as hCG and progesterone.
A study of EPF in women taking clomifene to treat infertility found fertilization rates of about 40%-50% per cycle. In cycles where fertilization was detected, nearly 80% resulted in subclinical embryonic loss, a rate much higher than that found in healthy women.
Here is the link: https://en.wikipedia.org/wiki/Early_pregnancy_factor