29 weeks symptom... (tmi)

I realise as soon as I hit 29 weeks I have been experiencing "the runs" or diarhea. My stomach doesn't hurt much and its not everyday. I was wondering if anyone experiencing the same. If it might be an infection, bacteria or just a pregnancy third trimester thinf. My next doctor appointment is next Saturday but if it continues I will schedule for Monday or Tuesday because I haven't experience such until now so I am a bit worried.