I can't get my BFP

Jessica
My first ever post here. Can someone please shed some light from similar experiences. 
My partner and I have been trying to concieve for 4 months now I'm 20 and he's 32. 
Since I was 16 I was on either the implant or on the pill. 
Got my implant taken out 5 months ago. I have done ovulation tests and have regular sex at the right time.  I have had regular periods. We both take multi parental vitamins for men and women. I was mistakenly diagnosed with PCOS a while back so I had examinations blood tests scans swabs and all sorts and I am completely healthy. This is really getting me down and upset. 
Anything will be appreciated. Thank you. 😘