Help! Crazy ex!

Sysylya
My boyfriend/ whatever we are have been talking for about 2 weeks relationship wise and have known Eachother for a solid 3-4 years. He is the ex of one of my used to be really good friends. But recently she has lost both me and him in her life. I helped him through the breakup and so forth. But im now seeing that my ex friend was a crazy person. Shes now claiming to be pregant which we all highly doubt she is but were taking 0 chances. She keeps threatening to kill herself and the baby if he gets with anyone else. But we want to be together. Seeing as we have a history as well as him and her. HOWEVER. we are both stumped as to what to do about her. any advice? 
And we are planning on having kids together. We have had that plan for 2 years now. Just waiting till the time is right.