I am in the same position. Bigger gaps than we planned, expected and wanted. My kids were born in 2000, 2007 and 2011. I have not been on contraception since DD3 was born (she is 3 this month) and we hope to add 1 more to the family.
Big gaps are hard too. My 2 eldest were 4 and almost 11 when I had no3. This meant DD3 was pulled from pillar to post for school bus runs (two different school buses, at 2 different bus stops, 40mins apart twice daily) not to mention athletics, swimming lessons, tutoring etc. You deal with the gaps you have when your babies are born and when you have another baby you know that it is the baby you were destined to have. Because of the gaps between my 3 children they all are separate. I expect if and when I have a 4th baby that will be the same. If I were to get pregnant now there would again be an almost 4year gap between my youngest and new baby and over 14year gap from no1 and no4.