I Had The Copper Coil Removed On The 4th Feb

I had the copper coil removed on the 4th feb this year after having it for nearly 5 years i always got my period on time.. Since having it removed i have had unprotected sex and i am now 3 days late for my period iv took hcg tests and they are negative and today i did a clear blue which was also negative could i be pregnant but too early to show? Iv had a lot of symptoms too such as headaches tiredness sickness