So my little girl will be 6 weeks pregnant on saturday ..well it will be 6 weeks since the last mating, her belly isnt huge as i thought it would be by now but she has got quite a big bulge only on one side her teats have got a lot bigger also, i will be taking her for a scan on tuesday nxt wk, is it normal that she only seems to be bigger on one side, this is her 1st litter.

I guess you will know Tuesday if she is in whelp.

There is nothing to suggest the puppies are going to be evenly spread on both sides of the uterine horns.  I guess you'll know what's going on with the scan - or not because this isn't 100% reliable and only shows puppies or not, at the time of the scan.