Could i be pregnant?

Milica

Hello everyone. I need your help. My period has started on 18/12 and last 3,4 months I had 27 days cycles. I had sex on 30/12,31/12,01/01. And now I didn’t get my period ( it’s 28 day of my cycle). I did clear blue digital pregnancy test this morning and it came out negative. Could I still be pregnant? Should I wait more or take some other pregnancy test? Blood test? Thank you in advance and good luck 😊