Hi, I have a question about possible pregnancy I had

Patient: Hi, I have a question about possible pregnancy. I had sex on the day after my last period(jan/7).I normally take birth control but had not yet started my next cycle of pills. I started my birth control pills on the evening of Jan 8. I am now currently on my 4th day of what should be my next period and have not started it yet. I took a pregnancy test but it came up negative. I am wondering if it is possible to be pregnant under these circumstances?

Doctor: Hello,If you have had sex on the day 2 of your cycle when you were already menstruating then it was your safe period and then you started on the birth control on the same day and were regular through out the month. this would have inhibited ovulation completely and hence no chances of pregnancy at all. Moreover your pregnancy test is already negative, so it is suggested that you may wait for your menses to return for a week as it may be delayed due to various stressors during the month which can cause hormonal imbalances over the birth control pill.i hope i have answered your query in detail,wishing you good health,regards