HCG Pregnyl 5000 IU Injection. What Is HCG Pregnyl Injection? HCG stands for human chorionic gonadotropin. It is a natural hormone that is formed in the placenta during early pregnancy and helps with the normal development of ova in women. It also plays a role in the stimulation of the release of the egg during ovulation. Dec 16, 2007 · I have to have 3x Pregnyl 1500 Injections ... HOWEVER - when you're having pregnyl boosters, they can give you a false positive on a pregnancy test so early testing becomes unreliable. Thread: Pregnyl in first trimester pregnancy. Pregnyl in first trimester pregnancy Calling on anyone who has used pregnyl during frist trimester pregnancy. A patient with anovulation or PCOS has trouble getting pregnant because her ovaries aren’t releasing eggs and may be given Pregnyl or another beta hCG to trigger ovulation. For women who don’t ovulate on their own, first they may have ovulation induced by being given a low dose of a fertility medication, such as clomiphene citrate (Clomid).