There were 5 girls, all friends, in my street. 3 were pregnant when they got married, 2 were not. 2 of the pregnant ones were later divorced. The other three of us are approaching our Golden Weddings. If I extrapolate to all my contemporaries, this was pretty average. I am older than the OP and the 'Pill' was brand new then and only available to married couples, usually after they had had one child and wanted to space out their family.
Life as a newly wed, in your late teens/early twenties, in a one bed flat or living with parents, and in many cases with a baby on the way, was pretty hard going. Some couples grew together, some grew apart.
Myself, I was lucky - four years of fun filled, childfree, married freedom, 2 jobs each, saved like mad and waited until we were allocated a council house before we started our family.
I think, Granzilla, that you were also one of the lucky ones. Life was not so rose tinted for everyone.