Mazal tov on your recent marriage!
We are sorry to hear of your difficulty conceiving, and about your miscarriage.
After a miscarriage, it can take a few months for the body to sort itself out. The fact that you conceived shows that for at least one cycle you were able to get to mikveh within your fertility window. In general, it is normal to take up to a year to conceive, and standard medical practice for women under 35 is to begin a fertility evaluation only after a year of trying. For all of these reasons, your doctor’s suggestion to wait another few months makes sense.
Ovulation typically occurs twelve to sixteen days prior to the onset of menstrual bleeding, and variations are normal, so it is likely that your mikveh night is not too late to conceive.
To clarify further whether you are ovulating prior to immersion, you could continue testing ovulation for another couple of cycles, starting the tests a few days before mikveh. If you do not find signs of ovulation, or determine that you are consistently ovulating before mikveh (as variations of up to a week in cycle length are normal), then you should present this information to your doctor, and discuss further diagnostic steps and potential treatment.
Halachically, to get a hefsek taharah as soon as day four, it can be helpful to know that the hefsek taharah bedikot need not be completely clear. Stains that are yellow or light brown (the color of coffee with milk) with no reddish hue are acceptable. Other questionable stains can be brought to a halachic authority for evaluation.
Please feel free to get back to us with any further questions. You may also find it helpful to read our site’s article about ovulation before mikveh and to schedule a consultation with a Yoetzet Halacha Fertility Counselor. (This is a free service. Details here.)
We wish you much hatzlacha!
This response was updated 22 October, 2020.