Could I be pregnant???

I had my cycle last month on December 19th - 23rd. My boyfriend and I had unprotected sex during my ovulation period. We didn’t use protection and he thinks he might have “pulled out” too late. I’m on cycle day 40 & currently 4 days late. About a week ago I started experiencing slight cramps that come and go & a bad migraine as well. My discharge is like a thin milky white lotion. I took a test the other day (January 25th) & it was negative. I’m still concerned about the chances of me being pregnant. I’ve been looking out for spotting and still haven’t seen any. Someone please help me !!!