Timing?

I got my first egg this past Friday and we have had an egg a day on everyday but Sunday. On Sunday my husband was out by the coop working on the privacy fence. There was a lot of hammering going on and the grandchildren were in the yard playing out by the run. I felt like it may have been too stressful for whichever is laying to do so on that day. I have it narrowed down to the BO or the BR that is laying, but on no day have we gotten an egg before 3:30 in the afternoon - however, this morning before 10 I heard a lot of cackling - from both the BR and BO and when I went out I had a morning egg. My question is on timing - do they lay pretty much the same time each day or can it vary like this. If she laid the other egg around 3:30 yesterday that was pretty quick to have another this morning. I'm wondering if two are now laying. If I have another egg this afternoon after 3 I will have answered my own question. The eggs are very small but the chicks are not bantams. Our neighbor told us that as they continue to lay that the eggs will get bigger. I sure hope so because it would take all five of these for an omlet. Regardless I couldn't be prouder that at least one of them as begun laying. We're in the midst of December but the days have been so mild I guess it has helped.