I am 16 weeks pregnant currently, got a called from ob that my placenta is little smaller than average. did some googling, i am really streesed out. is it something to worry or anxious about?

It is amazing all the data that Dr. Google can provide at a touch of the "enter" key. (smile) However,, 16 weeks is just the beginning of the 2nd trimester of your pregnancy and like your fetus, there is room for growth. Your OB MD will continue to monitor the situation as the pregnancy progresses, and please know that perfusion of blood to the fetus is probably still ongoing.