New to TTC after nuvaring

Alright so I had my period in January and left my nuvaring out as me and my husband decided we were ready to try. After I left it out I had a lot of pregnancy symptoms such as sore breasts, nausea, fatigue...but my period came on time in Feb. My husband and I had sex during my peak time (according to Glow). Since then, I have had strange cramps and a pulsating feeling as well as nausea, migraines, and no appetite. Yesterday I was in urgent care for the migraine and they ran a blood test which came back negative. If I am pregnant it would be exactly 1 week or less so is it possible it's too early for the blood test to tell?