It is heartbreaking to go through a miscarriage, let alone 3. I am so sorry.
To answer your question, yes. I have had 6 miscarriages and 3 children. It doesn't matter about your age, your GP should refer you to a recurrent miscarriage clinic or, at the very least, a fertility specialist. Please please do insist they do that, however much they try and fob you off.
You may find there is something relatively simple that can be dealt with by treatment or by something you take or do when you get pregnant again.
I had 5 years of infertility before I even had my first miscarriage and it was just so upsetting and so hard to keep going. I was diagnosed with unexpected infertility which is ridiculously frustrating! Lots of my blood test were just on the edge of OK and that definitely didn't help.
There is a great book that helps you understand your own body and cycle - Taking Charge of Your Fertility by Toni Weschler. That might help you get some idea what's going on or at least to understand the sorts of tests you might need.
It wasn't until I had 4 miscarriages that I got a different panel of tests. That identified a couple of potential issues including low progesterone which I had said was an issue but wasn't listened to. There was also a blood clotting problem. My next pregnancy then saw me use progesterone pessaries, take aspirin and inject blood thinners. It was successful.
I am so sorry you are going through this and I hope you get referred to someone who is more sympathetic and proactive in finding out what is going on.
I wish you the best of luck.