Rachel Nicholson, 23, is terrified about the serious damage the chemicals may have caused her unborn child.
Three weeks after she was given the dose, the singer-songwriter collapsed and was rushed to hospital where she discovered she was still pregnant.
She was overjoyed but faces an anxious wait as even though her baby somehow survived the medication, the chemicals mean there is an increased risk the child may be disabled.
Rachel said: “This has been the worst time of my life. I feel like I’ve had the first taste of motherhood – buying clothes, picking names and the excitement – ripped from me.
“Instead, I’m left with fear and worry.”
Rachel, of Barnet, North London, found out just before Christmas that she was six weeks pregnant.
In January she went with her partner to the nearby Edgware Pregnancy Advisory Service where a nurse failed to pick up a heartbeat on a scan and said the baby was gone.
Staff then gave distraught Rachel the abortion pill to prevent infection and to remove the foetus.
She was in physical and mental agony for weeks as her relationship with her partner disintegrated under the strain.
Rachel, who is now 17 weeks into the pregnancy, said: “As soon as I was told there was a heartbeat I burst into floods of tears.
“I don’t know how he or she will turn out but I do know I will love them whatever.”
Rachel, who suffered a miscarriage last year, is set for a scan next month when experts will check her baby for any deformities.
Fraterdrive Ltd, the private firm that runs the pregnancy centre, declined to comment.