Pregnancy bonus of 0.2 - that means that there's an increased chance to get pregnant.
E.G: Let's assume that it's a chance of 0.5 each time. That means that there's a 0.7 chance of getting pregnant, or 70%. I think that's right - it's an additive, so it's either 0.7 in that case, or 0.6 (0.2 times 0.5, then you add that figure to 0.5, which gives 0.6).