RISK OF PREGNANCY AFTER VASECTOMY

What is your question? I m a 30 year old woman who has been experiencing nausea the last 2 days also I am going to the bathroom very frequant. I am always late with my periods. Never monthly. I already have 3 children. My husband had a vasectomy 3 years ago but never had his sperm count checked is it possible for me to be pregnant. thanks