Spotting

So I had an early viability scan this past Monday and baby was measuring at 7 weeks 5 days with a heart rate of 134. Tuesday I had some light spotting but figured that was due to a combination of the transvaginal probe, scratching myself inserting a progesterone suppository and/or the sex I had monday night. Fast forward to Saturday and I have some light pink spotting and cramping but only on my left side. Should I be worried and at what point do you think I should call the doctor? Is there even anything they could do at this point to prevent a loss if that's what is happening?