What Causes Constipation With Brown Vaginal Discharge And Abdominal Cramps?

I am 26 yrs, height 5'2", weight 50kgs, missed my menstrual period for last 10 days. I had taken Pill 72 (after meal) within 3 hrs of intercourse (ovulating at that time) and checked for pregnancy test (HCG) - one clear line and other faint line (50% lighter shade).

Some symptoms i am facing for past 4-5 days are:
1. Constipation
2. Muddy brown discharge (approx twice a day)
3. Sudden cramps in lower abdomen and near pelvis
4. Slightly swollen breasts
5. High gastric

No feeling of nausea or faintness.

Am i pregnant or not? Please advise..