My Wife Had Cycle In The Following Days 12th August,

My wife had cycle in the following days
12th August, 8th September, 28th October ( after 40 days) and 1st of December.( after 34 days)
We had sex on 1st November and 06th December
Two urine tests and a blood test suggest pregnancy.
1. can this happen ?
2. We do need to remove pregnancy safely. She is 30 years Please advice on this
3. Can we do at home