If each pregnancy is 5050 chance of having a M or F what is the probability of having one F in two pregnancies or one F in three pregnancies Is it still 5050 on the second pregnancy?

Acutally the chances of having a boy are 51% and a girl 49%. The odds stay pretty close to 50% for each child and only vary slightly. If you have had 2 or 3 boys, you are only about 2% to 6% more likely to have another boy. If you have had girls, you are slightly more likely to have a boy next.