Overheard at the community health center

I'm walking through the lobby at my job, on the way from one side of the center to the other. I'm wearing my "business casual" with my ID around my neck, and a patient waiting in line locks eyes with me. She seems very excited to see me, though I'm pretty sure that we've never spoken to each other before...

Lady: HI!!!!
Me: How are you doing?

I keep walking as my rhetorical question has gone unanswered.

"HEY!" She has shouted this in an apparent attempt to stop me. I turn toward her and she pauses for a second as if she is not sure what she wants to say to me. "When is father's day?" She inquires innocently.

I stop, a little confused by the question, "Um..."

"The 6th of June? The 12th? Something like that, right?"

"Yeah, around there, probably the second Sunday..." I've slowed down my pace, but am still about to pass her on my way out of the waiting room.

"I'm just here getting condoms." she shouts to my back

"Oh..." I reply weakly, twisting around toward her b/c I didn't realize until this second that our conversation was continuing. "Good..."

She pauses long enough so that I start again to walk away and she sort of yells after me, "I come every month..."

I stop, turn, and am standing, looking at her from about 6 or 7 feet away.

"THEY'RE for my sons..." she continues, "15 and 17 years old... and they use them too..."

Pause. Pause. Pause

I reply, "Well that's good." She says nothing else.

I nod at her. She nods at me. Once again, I assume the conversation is over and turn to go. When I am another 10 feet away, she calls after me...

"SAFE SEX, RIGHT?!?" I turn back. She stage whispers this next part for no apparent reason, "SAAAAAFE SEX."

I nod. Then she retells the story to the person in line behind her.
I walk away having no idea what just happened.