First eggs - few questions

Well, we finally got our first eggs. I knew it would happen while I was in the backcountry for work. I have a few questions though.

We have 3 ducks and 5 chickens - all 19 weeks old. All the eggs so far have been from the ducks. I'm absolutely positive of this as they are laying at night and they are locked into separate coops. Of the three ducks, none of them are showing signs of a drake feather yet, but I can't be positive about the voice sexing. We are getting 1 egg per day. Four of them have been the size of chicken eggs and 1 was more what I expected from a duck egg. Is it typical to have inconsistency in size for awhile after they start laying? I would expect that if more than one of them were laying we'd have more than one egg per day. Is this correct? They've all been the same off-white/light tan color too.

I put a nest box in the chicken coop with some golf balls, but so far nothing. I'm being patient though and have started leaving a light on in the early evening, as our daylight is getting significantly shorter. Should I start expecting chicken eggs soon too? One of the other people that ordered at the same time I did has already gotten eggs from her chickens.

I did not put a nest box in the duck coop, as I truly expected them to lay out in the woods, after everything I've read. Should I built them a box too? They egss have had quite a bit of poo on them - although it's fairly easy to wash off.

Any advice is welcome!

 

Thanks, everyone. We are still getting the one duck egg consistently every morning. Patiently waiting for more or for a drake feather to appear. I've decided I will give them a nesting box, just to keep the eggs out of the muck.

Still no chicken eggs but I know it could be a couple weeks. We replaced the golf balls with a cream colored plastic egg. It's huge though, so hopefully it doesn't scare the girls too much!