Re: The flu :(
It irks me when docs tell women that progestin-only contraception is absolutely guaranteed not to affect milk supply. There is at least good anecdotal evidence that for SOME women, progestin-only pills do have a deleterious effect on supply. Since your LO continues to have good diaper output and you're continuing to have normal pump output, it's quite possible that you're among the majority of women for whom progestin-only contraception has no adverse impact on supply. But if at any point you feel like your supply is decreasing to the point where it is becoming inadequate, then you might want to think about alternative forms of birth control. You can always crowdsource your options here on the forum!
It's weird that you'd have the stabbing pain without seeing wedged nipples (indicating a latch problem). I wonder if perhaps your baby changed her latch recently in order to better control the milk flow? I am also wondering about something called vasospasm, which is a sudden painful constriction of the blood vessels in an extremity. If this is vasospasm, you might notice that it gets worse when it's cold, and you'd likely see the tips of your nipples turn white and then return to normal coloration, or perhaps go through a triphasic color change of white/bluish-purple/normal. If this continues, maybe put in a call to your local lactation consultant, preferably an IBCLC, for an in-person evaluation?
Coolest thing my big girl said recently: "How can you tell the world is moving when you are standing on it?"
Coolest thing my little girl sang recently: "I love dat one-two pupples!"