Question

If I had unprotected sex in December of 2023 and I get a period the end of December 2023, Januray 2024, and February of 2024. Could I get pregnant from that intercourse in March of 2024? Also, I took a urine pregnancy test at the doctor on January 31st, 2024 which came back negative. I am currently pregnant for 35 weeks I missed my period in March so my question is did I get pregnant from intercourse in December of 2023?