Belly pictures at 28 weeks

It has already been 4 weeks since I posted my last belly pictures. My belly measures 88 cm by now and as you can maybe see in the picture I am starting to show a linea nigra. I haven't been able to find what the use/meaning is of this line that runs from my belly button down, but it is just pigmentation.

So far my belly hasn't interfered much with my activities, but now I am starting to notice it more and more. During aerobics class last Friday I actually had a harder time with some of the exercises, and also bending over to dry of Clover's feet during the last couple of rainy days is more tricky. And Clover is testing me for it, b/c she is moving around all the time when I wipe her feet..... she mean.