What Causes Cramps And Bloating After Intercourse?

Dec 21st period two days late but regular and regular length 5.5 days. Jan. 13th "period" is 2 days early and just spotting for the 1st day.. 2/3 days are back on track and 4th day is brown and spotty. Sex the day after was followed with terrible cramps. Having mild cramps today and tons of white discharge. Its the 21st and I feel very strange, anxious, bloated and just overall confused feeling. Took a test this morning and I'm sure it was negative I think I want a positive so bad that my eyes played tricks. What does everyone think??