i am 28 years old and i have 4 years old boy and i am TTC for 1yearswith med (serophene,gonalf,profasi) then iui all the 6 of them faild then my dr told me that is the time to move for ivf he gave me last monday an injuction called arixtra he told me this the start of ivf medication that he can can control my ovulation he gave me told me to see him on aug 30 does that injuction stops my period to come because i am 4 days late i did HPT and its NEGATIVE what does that injuction do with ivf?