I am in a relationship with my best friend and partner. We are both female. If we marry and become ready for children...

If we both get pregnant at the same time, would the babies be twins whether or not they are born at the same time or day and from different mothers? If so I would then I would assume if we are both pregnant with twins then we would we have quadruplets that would possibly be born on different days and times. Its a curious thought is all.