Based on your symptoms, pregnancy is unlikely.
Meprate (medroxyprogesterone) commonly causes withdrawal bleeding, pink/brown discharge, headache, acne, and mood swings due to hormonal changes. Lighter-than-normal bleeding after Meprate is common and does not usually indicate pregnancy.
What to do next:
If there was a chance of unprotected intercourse, you may do a urine
pregnancy test after 7–10 days for reassurance.
Symptoms should settle on their own as hormones normalize.
See a gynecologist if bleeding becomes heavy, symptoms worsen, or cycles remain irregular.
This appears to be a medication-related hormonal effect, not pregnancy.