Triplet!!

So my boyfriend is a triplet. There would of been 4 of them but his mother miscarried one. She conceived them naturally. My question is what are my chance of having twin or triplets? They are the first on both side of there mother and fathers family. Their mom was super sick and almost died while she was pregnant with them so having three scares me because of the stories she has told me. It would be super cute to have twins though!