TTC over 2 years!

Hi,my husband and I have been having unprotected sex for over 2 years now and we already have a 6 year old son.We hoped it would just happen naturally and we didn't put too much pressure on TTC.However I'm turning 34 soon and our son is getting older and feel if it doesn't happen soon we will have a huge age gap.Can anyone give me and tips on using the app and also if you use ovulation tests too?Any advice would be great!TIA :\