Nope, she's legitimately heartbroken: Throws the knife down, runs across the room, and melts into a puddle of well-acted hysteria.
Facts: She lost the baby like right around the time they found Ian's fake suicide tableau. Which either does or really does not explain why Garrett started carrying her everywhere at that time, or why Wren was bringing her secret medications.
Melissa: "I tried to tell you about this the night of Ian's funeral, but then I found that phone in your bag and I thought you were the one sending me texts from Pretend Ian that whole time."
Spencer: "Fuck you! Why fake a baby?"
Yeah, lest you think that anything is getting to Spencer at this point. I mean, she's playing it with a fair amount of love -- if not sympathy -- but this shit is trainwreck central, so mostly she's just like, Are you effin' kidding me with these details?
Melissa: "I was confused! I was in a state of confusion! Ian's dead, I miscarried, it was a lot!"
Spencer: "You pretended that you were pregnant that whole time?"
Melissa: "At first it was just because I didn't want people to know my business. And then it just kind of spiraled into..."
Spencer: "Fuck all of this, crazy. Why were you at the Ball?"
Veronica: "-- I'm curious about that too. Hello, Melissa. Hello, Melissa's sister."
Hanna: "Fine, I'm going to tell Caleb like you said."
Aria: "Good. I know how hard this whole 'A' thing has been on you."
A: "I wouldn't."
Attached to the text? No big deal, just a picture of a car accident in Montecito, on the other side of the country. WHAT? This episode is fuller of things happening than the usual amount of things happening! Everything seems like it counts more, or something. Changes and craziness! So not only does A have spies in California, but also sets up car accidents? Or worse, what if Hanna's car accident powers are growing in scope? What if she can now cause car accidents all across North America? When will her mutant reign of terror end?
Melissa: "It starts with a package left at my house. The Black Swan dress was there with a note -- just like the one you Liars got, PS -- that said if I didn't attend some high school Masquerade Ball, my secret fake pregnancy would be revealed."
Spencer: "What? That's ridiculous."