I am also experiencing similar pain. I am 19 weeks pregnant and my belly button and the area right around my belly button hurt from time to time. It is sometimes constant but other days doesn't hurt much at all. I have been experiencing this for a couple weeks now.
The immune system is intricately connected to the hormonal system and the brain via messenger molecules, so that emotional stress and factors like insomnia have a great influence on its ability to function properly.
Insomnia is trouble falling asleep, staying asleep through the night, or waking up too early in the morning. Episodes of insomnia may come and go or be long-lasting. The quality of your sleep is as important as how much sleep you get. Sleep habits we learned as children may affect our sleep behaviors as adults. Poor sleep or lifestyle habits that may cause insomnia or make it worse include: