Can I use a regular sewing needle? No. It will be hard to get the jewelry through the piercing since its not hollow and will not give a clean, straight hole when you pierce it. It also increases you chance of infection, even if you sterilize it.
Thereof, is it dangerous to pierce your own belly button?
You should NEVER try to pierce your own belly button or any other part of your body! The risk of infection is very high if the right equipment isn’t used and if it’s not properly sterilized. The danger of an allergic reaction, bleeding, and scarring is also very real.