Sick since ovulation?

Obviously it's way to early for pregnancy symptoms...but since ovulation I've had the follow
1dpo- cramps (not like AF just light), tons of 'milky discharge' (no infection), headache and heart burn.
2dpo- milky discharge, headache, and heart burn
3dpo- milky discharge, headache, nausea and heart burn.
4dpo- milky discharge, HORRIBLE headache, nausea and heart burn, light cramps
What on earth could be causing this?:(