Getting Pregnant

I have never had a regular period, it’s never came on time. My partner and I are trying to get pregnant however I’m having trouble knowing when I’m fertile.

The ovulation test is telling me no but various apps are telling me I am.

We have only started trying and although we are excited I’m getting a little worried that this might be an issue.

I’m only 20 and I am aware I’m young so maybe not just have a gut feeling. If anyone could give some advice or tips, that would be great! Xx