Hello Dr My Period Date Was On 23rd December But

Hello dr my period date was on 23rd December but till now I have not got my period
I n my bf have sex on 12th,14th n 15th of this month (December) can I be pregnant
Last month also my period had cum after 35days Bcoz I had taken ipill
My period cycle is used to be 28-29 days. Always but this time I haven't got it still plz help