Ttc 2+ years

Hi all. Has anybody else been trying for what seems like forever to conceive their 2nd child. I'm almost 31 my partner almost 28. We already have a 4 almost 5 year old daughter. After my daughter was born i went back on the pill (microgynon) then decided to come off it in August 2013. Since then my periods have been quite irregular and some months I've missed a cycle. We've both just been to our doctors and he has had sperm analysis and been given the all clear. I'm waiting for blood tests next week to determine whether my hormone levels are were they should and if I've ovulated. I've had a positive opk today so know I am it's just so frustrating that nothing is or has happened yet. Is there any advice anyone can give me. I'm getting to the point were I seriously feel like giving up because I feel it's never going to happen for us. Please help!