Is it hcg?

So I've recently did the deed with my fiancé , and ever since been feeling sick ( nauseous, sensitive to a lot of smells , weird pains in my tummy, and just feel so different)I know it's way too early to test but I've been told ovulation tests can pick up hcg too? I've been testing for about a full week , I know I've reached my peak ovulation day already but I keep getting positive on tests? Also I took an hcg test just for the heck of it , and does anyone see a very very faint second line? Help!