When should I start with the pregnancy testing

Hi Ladies!!! I really need your help.

I'm only 7 dpo, BUT since wednesday (3 days ago) I'm feeling really weird. I have cramps, like if my menstruation is comming, but mostly in my right ovarium, also I'm really tired, sore breasted and on thursday and friday I couldn't stop crying all day, and I didn't know why!! It was like my tears where just coming from my eyes with no reason at all...today I woke up with nauseous...

So, my question is, it's possible to take a pregnancy test now?? When should I start testing ??

I'm new in this so I really need help.

Thanks in advance!!