early pregnancy signs of twins before missed period
1 Higher levels of hCG. 2  This may be reflected in a very early pregnancy urine test. 3  Even before a missed period, the level can be so high that there is an immediate, strong and clear positive confirmation on the pregnancy testing stick. This again, is a common pregnancy symptom but is exacerbated during a twin pregnancy. 2  Higher levels of hCG. 3  This may be reflected in a very early pregnancy urine test. 4  Even before a missed period, the level can be so high that there is an immediate, strong and clear positive confirmation on the pregnancy testing stick.