Hello Timeandmoney - welcome to the thread, nice to have you...iyswim!
As Bizzey has said 18 months is still very young, although I certainly knew my ds had eds before that, and the gp agreed. The most improtant thing for you at the moment has to be just to be aware, and keep a keen eye out on his development. Don't expect a lot of support from the medical profession as most on here would agree that support is not often forthcoming, however there is bags of support and a wealth of experience on here, whether it is a big question, a little issue, or just a chat! I will plump up the sofa cushions and make room for you by moving my substantial backside up a bit
I think it is a good thing to have gone to the drop-in centre yesterday, well done for facing that demon. I am sorry you felt a bit upset afterwards, but I can completely understand why.
As Bizzey says, don't worry too much about what you might read on here, most of our dc are older than your little ds, and some have some more complex problems which are out of the "norm" for eds/bjhs.
I am not sure how much you know, so forgive me if I am saying stuff you already know about....bear with me.
Ehlers Danlos Syndrome is a autosomal dominant genetic connective tissue disorder, there are several different types, most of which include a degree of joint hypermobility as one of their symptoms. Benign Joint Hypermobilty Syndrome is considered by most experts to be the mild end of the scale, but basically to still be EDS Type 3, There are people on here who have, and or their dc have different EDS types, have an BJHS dx or have Marfans. Some people have a clear dx, others are still struggling to get one. Some dc are just affected in their joints, others have more pronounced affects elsewhere in the body. The one thing I have learnt about eds over the last 22 years is that it is different for everyone.
My ds is 9, he was dx by Professor Grahame at UCHL when he was 20 months old. This is very unusual, Prof Grahame even said so himself at the time. I have EDS, and although he is my first ds I knew from birth he had it, he was too flexible. He was late to crawl, roll over and walk, but not excessively so. His fine motor skills were always excellent, picking up small objects etc. I knew that his joints just moved too far. I knew what to expect but still in hind sight I can see I missed pain signals from him even as a small child. He cried too much when he tried to roll over, his shoulders were subluxing.....I didn't realise at the time. At 3 he regularly complained of leg pain, particulary mid calf, and had terrible cramps. It was only when he was school age that I started to notice real differences with his peers. He tired easily, he struggled to be able to dress himself, his handwriting was poor, he would sublux fingers and knee caps very easily. At 6 he really developed the probelms he has now, he dislocated his cervical spine, shoulders, knees, fingers and hips. His handwriting deteriorated rapidly, he was in severe pain nearly every day, his gross motor skills were very poor compared to peers, he also started fainting and having vasovagal episodes, lost weight and had poor weight gain.
Depending how you rate your gp, would determine what I would do next. It is really difficult to spot whether they are in pain or not, but if you think he might be, and your gp is a "friendly" I would pop along and discuss your concerns, whilst acknowledging that it is early days. A rheumatologist is best placed to make a dx, although some gp's refer to Paediatricians, having said that they might not want to make a dx at this stage. Still a chat about what to look out for might be reassuring for you. A physio is not qualified to make a proper dx, although they will have a very good idea. My ds has an excellent physio, but she always says we have to check things out with the rheumie.
Bottom line, don't worry, most people who have eds/bjhs have little or no problems at all, try and remember that.
Sorry that is a bit of a marathon post....did it help.