Already pregnant, could i get on my husband's insurance in july?

Sorry! im asking alotta questions on here but only because this is my first pregnancy and i wanna know everthing possible. I husband works full time and last year we didnt enroll in his jobs insurance because it was to much $$, the next enrollment date is in July but im 4 weeks prego now. Will his insurance deny me or cover me if we decide to get it?