Until now, most abortions in Florida have taken place later than six weeks of pregnancy. The new law will replace a 15-week abortion ban that Gov. Ron DeSantis signed into law in April 2022, shortly before the U.S. Supreme Court overturned Roe v. Wade.

Later on Saturday morning, as patients left the clinic, protesters encouraged them not to take their abortion pills, or to “repent” if they had already completed the procedure. One patient got into the driver’s seat of an S.U.V., where a man had waited for hours along with a dog and baby in a car seat.

Ms. Dye said that A Woman’s World performed more than 700 abortions last year, out of the nearly 84,000 that took place in Florida. Most patients are 18 to 36, she said, though one of the patients on Saturday was 43. The oldest patient the clinic has ever provided with an abortion was 51; the youngest was 11.

In 1988, while in recovery for a drug addiction and after a stint in prison, Ms. Dye found a job as a receptionist at an abortion clinic in nearby Port St. Lucie. Taking calls from women looking for help gave her purpose, she said, and she credited her work with keeping her sober since.

“If I have to close my doors,” she said, “I’m going to open a halfway house for women in recovery.”

But she hopes that it will not come to that. Her husband, daughter, granddaughter and niece all work at the clinic. Ms. Dye has set up a fund-raising page and plans to keep the clinic open, providing ultrasounds and abortions up to six weeks, for as long as she can pay the bills.

On Monday, she answered a call from a woman nine weeks along who wanted to end her pregnancy. She told her she would not be able to help her, and that she would almost certainly have to seek an abortion outside of Florida.

Susan C. Beachy and Kirsten Noyes contributed research.