Dog insurance is it worth it?

I have a chuahua puppy which l love to bits he has had his first jabs today and worm tablet,ive heard many things about dog insurance,im just not sure,hes so small that he will never be off his lead,our garden is made safe for him as is the home,i know he can get ill,but on the whole i can afford tablets or injections,its the whole operation thing that worries me,i dont want to be paying every month and getting no use out of it,then ive heard that the insurance companys always try to crawl out of it anyway,is it worth the hle,anyone dealt with these companys before in the uk?please note i am a kind caring and loving pet owner,i am not saying i wont keep my pet healthy i am simply deciding weather to do it via insurance or our of my own pocket.thanks