No. You can not connect to your own IP address from http://www.mijnip.nl. This would only work when your router had NAT loopback, which is not the case for most routers. You normally only can connect either to an online server on a really different location with a different IP address, or to a local server on your LAN through its server name or local IP.

All this is mentioned in the multiplayer workshop, so make sure to read and understand that first. This forum is mainly for questions that aren't answered elsewhere.