It's more common than I thought, according to fellow cartoonist and mother Kelly Ferdinando: "'Morning sickness' is quite the misnomer. It can happen any time of day."
TRANSCRIPTION COURTESY OF JOSEPH HOUK - (Dad, in the middle of Tryptophan overdose) "I ate so much I think I'm gonna burst!" (CW, sweating bullets) "Same here… heh…" (Mom) "Well, you have an excuse… You're eating for two, right?" (CW) "Well, uh… yeah!" (PW, whispering) "Everything okay?" (CW, whispering) "My fake belly is coming off!" (PW, whispering) "What are you gonna do?" (CW, whispering) "I don't know. I just need to get out of here… gracefully, if possible!" (Mom) "I want to feel for a kick ag-" (CW, ungracefully holding her mouth – and "bump") "Ulp… GANGWAY!!!" (Mom) "Oh dear… Cassie, you alright?" (Sonya) "I hear some people get morning sickness in the afternoon. Maybe that's what's going on…"