Doctors have now warned the singer to put her feet up for a while and take things easy.
A source close to the star, who is rumoured to be expecting twins, revealed that she was petrified that she might miscarry.
"She's petrified that something could go wrong (with her pregnancy). (The hospital visit) really shook her up. If she lost the babies, her life would be shattered," Contactmusic quoted the source, as saying.
And, JLo and her doctors are not the only ones who are worried sick, for so is her mom Guadalupe.
"Her mum's constantly been on the phone, telling her to calm down. Guadalupe's very no-nonsense and she's told Jen that she needs to take some time out of the limelight to enjoy her pregnancy and her babies when they arrive," the source said.