I'm a big cranky mess this morning. I woke up in a good mood, and some stupid technology issues made me want to transform into a dinosaur and go stomp on small towns. Raaaaar. All because I missed The Price is Right and Facebook has made my groups harder to see... Ridiculous... I'm working on distracting myself now so I don't go full Pregzilla. I'd hate to see my freakout if I had a real problem!
As for weeks vs months. I use weeks with people who I suspect might care to that amount of detail. If it's someone I just know casually, I usually round to the nearest half month. I figure some random lady I tutor with is just making conversation and wants a rough idea, so 4 1/2 months is close enough, whether I'm 17 or 19 weeks at the time. I don't think people who haven't been pregnant are too familiar with the week system.
I'll post photos at 7 weeks, 16 1/2 weeks (I think that's what you said you posted), and my most recent from a couple days ago at 18+2 I think. I usually take them before I eat, and the most recent one is after eating, so it shows a little more growth than I really had. I think your bump looks great for 16 weeks. People just get this idea of what pregnant women should look like, and they don't realize how much variation there is in normal. And then the ones who wish they looked thinner when they were pregnant will think "You look so small!" is a compliment, and meanwhile you're sitting there wishing the bump would just get big already. It's such an emotional minefield.