Luteinizing hormone, also known as progesterone, is pulsatile secretion during pregnancy, which means that the measurement time is different, it is possible to be different, down to 21ng/ml may be normal or abnormal, need to be combined with HCG and ultrasound to make a comprehensive judgment.
Luteinizing hormone in early pregnancy should be in the range of 30~50ng/ml, simply looking at the data, 21ng/ml is on the low side. However, if the HCG doubling is normal, the fetus has fetal heart and buds, and there is no other abnormality, there is no need to worry too much.
If you have had a miscarriage before, or if you have vaginal bleeding or abdominal pain this time, you should be alert to the situation of preeclampsia or embryonic arrest, and you should have an ultrasound to confirm whether the fetus is alive or not, and carry out fertility preservation treatment to prevent accidents if necessary.