Hello there :)
Kidney infections, depending on the severity can have an impact on the menstruation which would have a direct relation with difficulties when trying to get pregnant. However this depends on how severe it was and how healthy your kidney is nowdays.
If you're affected by a cronical kidney disease, you'd most likely have irregular periods, hormonal disorders which would have a relation with your ovulation and the best time to try to get pregnant.
However if your kidney is pretty much ok and you didnt suffer major complications with your infection it should not really affect your menstruation.
If you do have an irregular menstruation, stress issues (A bit due to the desperation of having difficulties) or hormonal disorders it may bring complications when you decide to try to get pregnant.
I'd highly suggest you and your fiance visit a doctor and try to get a picture of the current situation if you're interested in getting pregnant before August, as it might take a time under good circumstances, it might help you out on your objective, specially since there is a wide variety of issues that could raise difficulties when attempting to concieve as I mentioned before.