Salty taste in mouth?

My son will be 7 months on the 1st, we are trying for #2 and my period has not returned since DS was born. I've been feeling some cramping, and have been tired the last week or so. Normally, my first sign of pregnancy is severe exhaustion, but realize my symptoms may be different as I'm still breastfeeding. Foods I normally eat seem more salty & despite drinking a liter or more water today, have noticed a salty taste in my mouth. I've taken 2 HPT which were negative, but with my son is didn't have a positive HPT until about 6 weeks. Has anyone had a salty taste be an early signs of pregnancy? I feel like I am, but will just wait it out..