Odd pain

So I'm almost 6 weeks pregnant. This morning I had this weird throbbing like pain in my lower left abdomin. It comes and it goes. Every minute or two I feel it. It only lasts a few seconds. But it comes like I said every minute or two constantly. It went away  this afternoon but is now back. Initially I chalked it up to gas. But it's still a little unnerving. I have an existing dr appt Wednesday morning.  I'm going to bring it up.  Hopefully it's nothing. Anyone ever had weird aches/pains? My mind immediately goes to worse case problems like ectopic or MC. This is baby 2 but my daughter is almost 10 so it's been almost 11 years (including her pregnancy) since being at this stage so I have forgotten almost everything. 
Thanks for any positive thoughts or reassurance.