Using qplot() in R: y label is not appearing

Question

I am using qplot, but am having difficulty adding a label to the y-axis. I am using + ylab("My y label") to the end of my qplot functions. It does not cause an error. A plot is generated, but the y label cannot be seen.

Here is toy data:

x=c(1,2,3,4,5)
y=c(7,2,6,3,9)
xstart=c(5,2,7,3,6)
ystart=c(1,4,5,8,2)
xend=c(4,7,2,7,3)
yend=c(4,6,8,3,8)
diagx=c(1,-1,1,-1,1)
diagy=c(-1,1,-1,1,-1)
myLab=as.factor(c("text1","text2","text3","text4","text5"))
df=data.frame(x,y,xstart,ystart,xend,yend,diagx,diagy,myLab)

And my code to generate the plot (notice the last line):

myPlot = ggplot2::qplot(data=df, x=x, y=y, label=myLab, geom="text", vjust=-.25, hjust=.5) +
  ggplot2::geom_segment(ggplot2::aes(x=xstart, y=ystart, xend=xend, yend=yend),inherit.aes=F) + 
  # Draw the underline of the variety
  ggplot2::geom_segment(ggplot2::aes(x=xend, y=yend, xend=diagx, yend=diagy),inherit.aes=F) +
  #ggplot2::facet_wrap(~variety, scales="free", ncol=2) +
  ggplot2::scale_size_continuous(range=c(3,3),guide="none") +
  ggplot2::scale_colour_identity() +
  ggplot2::theme_bw() +
  ggplot2::theme(axis.title=ggplot2::element_blank(), 
                 axis.text=ggplot2::element_blank(), 
                 axis.ticks=ggplot2::element_blank()) + 
  ggplot2::scale_x_continuous(expand = c(.1, 1.075)) + 
  ggplot2::scale_y_continuous(expand = c(.1, 1.075)) +
  ggplot2::ylab("My y label")

If you have any advice, please let me know! Thanks.