Dear Doctors My Spouse LMP Was 08th February 16,but She

Dear Doctors

My spouse LMP was 08th February 16,but she missed her period on March 16 and we checked Home Pregnancy Test on March we found negative result.

We consult Doctor for check up and she prescribed Blood test,the result was also negative and then she prescribed Ultra sound pelvis test in that test we found
Uterus:

AVF,normal in size(97*43*54mm) showing homogeneous echopattern.no fibroid or mass seen.

The endrometrium is thick,echo genie &a measure (17.4mm)

Both Ovaries:

Are normal in size and echopattern.No detectable cystic and solid mass lesson.
Right overy measures 46*21mm.
Left Overy measures 44*21mm

No adernexal mass lession seen.
No free fluid seen in the cul de sac.

Doctor prescribed medicine Duphaston tablet 2times/day and for 10days.

Now 9days got completed and little blood spotted observed.

We would like to know the purpose of that tablet and the problem what she have.

If any suggestions can be provided please