Thanks for the query to H.C.M. Forum.
You mentioned that the last period was on TIME but lasted for 2 days.
Again period ( after one month but 4 days late) stated but lasted for 2 days , but light.
All symptoms you mentioned as mood swings, cramps, fatigue
, sickness, tender breast , nipples indicates pregnancy
but pregnancy test is negative even after 2 months time ( 1st & 2nd period as mentioned above).
In my opinion all these symptoms are due to tension ( stress
) of conception and is an indication of pseudo pregnancy.
Still , if doubt consult gynecologist and physical examination will clear all things.
Good luck. Dr. HET