You have not mentioned whether you missed a period.For conception to occur there is no need for complete penetration. Sperms deposited on the vaginal opening can also lead to pregnancy
. The exhaustion,nausea
and other symptoms are observed in early pregnancy but they could also be due to electrolyte imbalance
and water logging. Try getting another pregnancy test and follow it up with an ultrasound
study in consultation with an obstetrician.Good luck.