I think that i am tearing ... at 16 weeeks preg!!!!?

You aren't tearing. It can be hemherroids or a yeast infection. A yeast infection can actually cause the skin to start breaking down which can lead to bleeding. The hemherroids can also cause bleeding and stinging. Either way you need to go to an emergency room and be seen so they can figure it out and get you the proper medication for your problem.