Hello,
When used correctly, birth control patch is 99% effective. Each patch lasts for 1 week. If you use it correctly, chances of you getting pregnant are very very meagre. As you are having greenish discharge, it might be due to
vaginal infection. The following are few probable causes of pain in
uterus region and vaginal discharge:
1) Pelvic inflammatory disease
2) Vaginal trichomoniasis
3) Bacterial vaginosis
Treatment depends upon the cause of infection. Mostly
pregnancy is not possible as you are on patch. If the patch is expired and you have had sex after expiration of patch, then pregnancy may be considered. You can go for urine pregnancy test at home. You may need to consult a gynecologist for examination in person of vagina and initiation of treatment.
Take care. Hope I have answered your question. Let me know if I can assist you further.
Regards,
Dr. Pallavi M., Anesthesiologist