Random questions and slightly a bit gross (TMI)

I’m on cycle day 22 of a 28 cycle so I’m in the luteal phase. I’ve been trying to conceive and been having sexual interactions last week due ovulation. I’m just wondering these things

1) is it’s possible to be experiencing early pregnancy symptoms this early?

2) is it normal to have diarrhoea at this stage in my cycle?

3) when would be a great time/day to start testing for pregnancy?