Loving family

Ok so me and my husband have been together for 15years married for 8 years. We have three children 10,6,4, we live in a rural area with a little doggy. We own a wholesale plant nursery where we both work and have a team of people who help us too. We get on incredibly well and enjoy the freedom of working together as it means whatever goes. 
We are currently trying and both are healthy for pregnancy, but it's just not happening been trying every other day, we are unbelievably happy no arguments very laid back type of people no stress. 
With all my children I got pregnant within the first month this time it's been four.
I feel like its something saying you've got three what more do you want!?!? 
Am I mad, well actually I know I'm mad but is it unreasonable or stupid to want one more.
To all the ladies who don't have any I apologise this to you must seen greedy and hope you are blessed soon but I would just love one more we have a empty chair at our table it makes me incredibly sad to think it might not happen.
My husband is so supportive and we have booked days off work to go away have massages, enjoy each other, laugh and dinner dancing etc...
Just hope soon it's going to happen 🙏🏻
Thank you all for taking the time to read and any comments would be greatly recieved 😘