"The flea" Interpretation

I think "The Flea" by John Donne is about a just married man and woman who get pregnant and have a baby--"And in this flea our two bloods mingled be. . . And pampered swells with one blood made of two. . . Where we almost, nay more than married are"(4,8,11). Then he kills his wife, child, then self--"Though use make you apt to kill me, Let not to that, self-murderer added be, And sacrilege, three sins in killing three"(16-18)Then he thinks it over more and says how the baby is innocent and hasn't done anything wrong--"Wherein could this flea guilty be, Except in that drop which it sucked from thee?"(21-22) Then explains that killing the baby is what made him want to kill himself--"Will waste, as this flea's death took life from thee" (27).