Cycle buddy?

AF due 7th September. I'm 24 and have been TTC for 2 months almost. I came off BC early July and was lucky enough to fall pregnant without AF visiting. Unfortunately I had a chemical pregnancy. I'm TTC straight away and wasting no time 👍🏼 I'm using opk's for the first time as of today but due to the chemical I know my cycle may be off a little. I'm a non drinker, work too much and desperately want to have my children young. I'm from the uk.