Opinions please!

Sandy
My husband and I have been trying to conceive however this is the first month we've tried so I wasn't really expecting to get pregnant. We did time ovulation and all that stuff though. My period is now 8 days late but I'm still getting negative tests. I have been feeling kind of fatigued lately and yesterday I was sick and tasting stomach bile all day. I have also noticed a stronger smell to my urine even when it is light in color. My period has always been a perfect 28 day cycle and I'm never even a day late. Any thoughts? I keep thinking I may be pregnant but the tests are all negative so I'm confused. This would be my first pregnancy. What should I do next?