Hello Mam I Had Sex With My Gf On 15

Hello mam
I had sex with my gf on 15 oct 2016 and after that she missed periods than in dec again period comes only for a while then again in jan period missed but after cheaking by pregnancy tester after 6-7 days having sex result is negative than we have again cheak by sugar test than again it is negative so in this cndition is she pregnant bt we have sex with protection