Could Short Periods Along With Nausea And Fatigue Be The Symptoms Of Pregnancy?

I had unprotected sex on the 23rd of January. I taken a pregnancy test and the line was extremely faint yes. Following that there were negative test. I ve experienced nausea, extreme fatigue, having to urinate alot more. I recently had my period which was shorter than normal (same flow) on the 11th of February. My period lasted for about 2 days (I m on the pill, it usually last for 3 to 4 days). It ended around the 14th of February. On the 16th I ve started spotting dark brown and it s been off and on since.