Cycle Day 9 Cramping and Spotting During Letrozole Treatment
Your symptoms of mild cramping, cervical mucus, and light spotting on cycle day 9 are expected physiologic responses to letrozole-induced ovarian stimulation and do not indicate a problem. The dramatic FSH fluctuation you describe (12.2 IU/L on day 7 dropping to 2.4 IU/L on day 9) reflects normal negative feedback as your follicles mature and produce estrogen, which is precisely how letrozole works 1.
Understanding Your Symptoms
These findings are entirely normal for this stage of your cycle:
Cramping on cycle day 9 represents follicular growth and stretching of the ovarian capsule as your dominant follicle(s) enlarge in response to the letrozole stimulation 1, 2.
Cervical mucus production indicates rising estrogen from maturing follicles—letrozole does not deplete estrogen receptors like clomiphene citrate, so normal cervical mucus production is preserved and actually indicates successful ovarian response 1.
Light spotting at this point in your cycle may represent either mid-cycle estrogen breakthrough bleeding as follicles mature, or early luteinizing hormone (LH) surge-related changes 3.
What These Hormone Changes Mean
The FSH rise to 12.2 IU/L on day 7 occurred because letrozole blocks estrogen production, removing negative feedback on your pituitary gland 1.
The subsequent drop to 2.4 IU/L on day 9 indicates your follicles are now producing estrogen (despite letrozole), which restores negative feedback—this is the desired effect and suggests you have responsive follicle(s) developing 1, 4.
This FSH pattern promotes mono- or oligo-ovulation rather than excessive multifollicular development, because estrogen receptors in your brain remain functional with letrozole (unlike with clomiphene) 1.
What You Should Do Now
Continue your current course and monitor for ovulation:
No intervention is needed for these symptoms—they indicate appropriate ovarian response 1, 2.
Begin monitoring for LH surge starting now (cycle day 9-10), as ovulation typically occurs 12-14 days after starting letrozole at your dose 4, 5.
Expect ovulation around cycle days 12-14 based on the typical timeline with 7.5 mg letrozole 2, 4, 5.
The cervical mucus you're experiencing is favorable for conception and should not be suppressed—this is an advantage of letrozole over clomiphene 1.
When to Seek Urgent Evaluation
Contact your provider immediately if you develop:
Severe abdominal pain or distension (could indicate ovarian hyperstimulation syndrome, though rare with letrozole) 6.
Heavy vaginal bleeding (more than light spotting) 3.
Positive pregnancy test with worsening pain (to rule out ectopic pregnancy if you conceived in a prior cycle) 3.
Important Context About Your Letrozole Dose
Your 7.5 mg dose is higher than standard but is supported by evidence showing increased follicular development and pregnancy rates compared to lower doses 2, 4.
Studies show 7.5 mg produces more mature follicles than 2.5 mg without detrimental effects on endometrial thickness 2, 4.
However, 7.5 mg does not show clear advantage over 5 mg in head-to-head comparisons for ovulation or pregnancy rates 5.
Your endometrial thickness should be monitored as letrozole combined with gonadotropins (if used) can thin the endometrium, though this is less concerning with letrozole alone 7.
Expected Timeline Going Forward
Ovulation should occur within 3-5 days (cycle days 12-14) based on your current symptoms and hormone pattern 4, 5.
Plan intercourse or insemination when LH surge is detected or when your largest follicle reaches 18 mm on ultrasound 4, 5, 7.
The spotting should resolve within 24-48 hours as you approach ovulation 3.