Talk to Gynecologist on Conception

I'm 28 and my husband is of 30. On 31st Dec,2018 I had C-section and lost my premature baby on 1st jan..(pre-eclampsia Is the reason behind all this and it happened in 29th week of pregnancy) it's been three months..due to pregnancy acne I have taken Isolit as prescribed by dermatologist till 15th march..this pill causes birth defects..we are using condoms as a precaution but few days back we forgot to use condom and pre-cum of my husband's touched my vagina.. we didn't do intercourse nor he ejaculate into me.. please tell me can there is a chance of conception ? If yes, how can I prevent it