messed up cycle help!! 7 days late

I'm 4months PP only gotten two cycles (was nursing) both were 28 days apart (like before pregnancy) and now I'm in cycle day 36 ... I did take a test negative that if I look at long enough i see a line but I know it's "line eye"(will post)  I haven't taken anymore bc we live in a small town and have to drive 20 miles to get them... anyone else's cycles messed up?!! How long does it take going back to normal? Side not I'm not on the mini pill I was prescribed yet but we "withdrawal" and barely do the deed ... y'all parents with newborns get my drift 😉