Reduced Menstrual Flow After Devry (Dydrogesterone) Is Likely Not Pregnancy-Related
Light menstrual bleeding after taking dydrogesterone (Devry) following levonorgestrel emergency contraception is a common hormonal effect and does not indicate pregnancy, though pregnancy must still be formally excluded with testing if menses is delayed beyond 3 weeks. 1
Understanding the Bleeding Pattern
The reduced menstrual flow you're experiencing is most likely due to the hormonal effects of both medications on your endometrium:
- Levonorgestrel emergency contraception commonly causes menstrual cycle alterations, including changes in flow volume, timing, and duration 2
- Expected side effects of levonorgestrel include "changes in your period, such as a period that is heavier or lighter or a period that is early or late" 2
- Dydrogesterone (Devry) is a progestogen that stabilizes the endometrium, which can result in lighter withdrawal bleeding when discontinued 3, 4
Why the Flow Is Reduced
The combination of these two hormonal exposures explains the light flow:
- Levonorgestrel works by delaying or stopping ovulation, which disrupts the normal hormonal buildup of the endometrial lining 2, 5
- Without adequate estrogen-driven endometrial proliferation, there is less tissue to shed during menstruation, resulting in lighter flow 3
- Progestogen-only medications like dydrogesterone can cause irregular bleeding patterns and reduced menstrual volume 6
Excluding Pregnancy
While the light bleeding is likely hormonal, pregnancy must still be ruled out:
- You should perform a pregnancy test if you do not have a withdrawal bleed within 3 weeks of taking emergency contraception 1
- Pregnancy-related causes such as ectopic pregnancy, threatened abortion, or early pregnancy complications must be excluded first with a urine or serum β-hCG test 3
- If your period is delayed beyond 1 week from the expected time, pregnancy is possible and testing is mandatory 2
When to Seek Immediate Care
Certain symptoms require urgent evaluation:
- If you have severe abdominal pain, you may have an ectopic pregnancy and should get immediate medical attention 2
- Hemodynamic instability or bleeding that saturates a large pad or tampon hourly for at least 4 hours warrants urgent evaluation 1
Expected Timeline
Understanding normal timing helps distinguish hormonal effects from pregnancy:
- Emergency contraception can cause your next period to come early, late, heavier, or lighter than usual 2
- The cycle in which emergency contraception is used might be shortened, prolonged, or involve irregular bleeding 1
- Most bleeding irregularities after hormonal contraception are not harmful and resolve spontaneously 4
Bottom Line
The light flow after taking both levonorgestrel and dydrogesterone is an expected hormonal effect rather than a sign of pregnancy. 3, 2 However, perform a pregnancy test if your next period is delayed by more than one week or if you don't have withdrawal bleeding within 3 weeks 1, 2 to definitively exclude pregnancy.