It happened around 9:30 p.m. near Emerald and Clarence streets in the Port Richmond section of Philadelphia.
Police found the 18-year-old victim unconscious in a car after the driver tried to reverse down the 3500 block of Emerald Street to escape the gunfire.
Moments earlier, the car was stopped as the victim spoke with a friend on the corner.
"The passenger may have known a male that she saw, on the corner, they stopped and talked to the male, then shots rang out," said Philadelphia Police Commissioner Richard Ross.
The teen, who is believed to be 2 months pregnant, was hit three times in the chest and torso. She was transported to Temple University Hospital in critical condition.
"We don't know if this was an issue of crossfire, or if they were shooting at the male I alluded to, we just don't know," said Ross.
With the crime scene tape gone and the sun up, Amina Sheppard is assessing the damage to her car that was parked on the corner of Emerald and Atlantic streets.
"This one right here, this one right here," said Sheppard, pointing to a bullet hole, "It went through my mirror and came out right here."
Police said at least 30 shots were fired.
At least three nearby homes were also struck, but no one inside was hurt.
"There are bullet holes at the bottom of this house, in that window. That shot through this house and almost hit them. They were just shooting all over the place," said Sheppard.
Jose Colon's home has five bullet holes in it. At least one of the bullets made its way inside and fractured a hanging picture.
"Too many bullets, shots," said Colin. He described the sound, "Bang, bang,bang, bang."
No arrests have been made.
Anyone with any information is asked to call police at 215-686-TIPS.