I have a 4 year old and fell preganant over 2 years ago but miscarried at 12 weeks

I have a 4 year old and fell preganant over 2 years ago but miscarried at 12 weeks. We have been through the fertility clinic procedures, had the necessary tests done and have been told no reason why we should be struggling. Having nearly given up hope, I joined this app, purchased some sachets called Proxeed online and some fertility lubrication to try. I held off testing this month for some reason (possibly to avaiod the usual disappointment and was completely shocked to discover that I was in fact 2-3 weeks pregnant. I'm not sure what it was that made a difference last month, but one, or all 3 changes seemed to make the difference. I have been experiencing a lot of pain, but also many strong pregnancy symptoms, so it's now just a waiting game for the 12 week scan to find out if we have a successful pregnancy. It's difficult to get exciting, just in case but trying to remain positive non the less.