Hi There, I Am Late For My Period (8 Days

Hi there,

I am late for my period (8 days now) when I was due for my period I had slight spotting but nothing since.
Over this last month I have been exercising a lot and taking supplement shakes for lunch and dropped 5 kg.
Now I am getting sharp stabbing pain in my lower left abdomen. It comes in waves and sometimes I have to sit for a few minutes until the pain has subsided. I haven't done a pregnancy test yet as I don't feel any different aside from the pain.
I have had the same stabbing pain a few months ago during ovulation time and then period.
I'm not sure if I should go to my GP or just wait for a few more days.