Any advice....

So my husband and I have been ttc for 4 years. Been tracking my period for about a year now. We just had our first appt with fertility specialist. Got blood taken, hubby did his SA and we’ve just been waiting for me to get my period to do 3rd day bloods and hsg.

So I’m 19 days late for my period. Have tested multiple times, all very negative. Talked to the fertility place and they said wait another week but then they could give me something to induce a period. My periods can be late but usually 5-8 days late....not 19!!

Will they check my blood before inducing the period? Has anyone had this happen??