The vitamins I use are pregnacare and they come recommend by my IVF clinic x
I'm currently taking Pregnacare and I've been tracking Aunt Irma for years now, so my tracking application also shows when I'm my most fertile, so I'll be using that too. Recommend tracking that'll give you a better understanding of your cycle and ovulation. We too are trying for no.2 (first time was a naive "I won't get pregnant straight away first time" thought 😂)
I just started taking pregnacare straight away and I would also recommend tracking ovulation, download premom app and you can upload ovulation test pics. I got some easy@home tests from Amazon