Has anyone encounter this?

[KimWright16]

I use an app to track my ovulation date. It gave me an window from Nov. 13-19 with the 18th being my most fertile day. I don't know how accurate it is. My bf & I had unprotected sex on the Nov 13th. I know sperm can live for 5-6 days so it's possible it made it to my most fertile day. I have since then being nausea with mild period like cramps and lower back pains. I never been nausea before in my life. I got my lady friend on Dec 4 it was a day late l. I still feel nausea with lower pains. I can't take a test until 27th. Just impatient & wondering if anybody encounter this. Please help!