Emotional idk y

It’s my first pregnancy 19 weeks and I’m 28 years old I’m so excited and over the moon. But today I can’t seem to get out this funk of feeling down and depressed. My fiancé wants to go to dinner or a movie for Valentine’s Day and I’m just so short answered with him. Like honestly I’m just sad I have no jeans that I can fit I’m over wearing leggings I feel so ugh. It’s been bothering me every time I open my closest today and realize nothing in there fits me. I’m usually very happy relaxed and joking around, but today I just feel ugh. Idk what’s wrong or why I feel this way never have I ever felt like this. I love my baby and can’t wait to meet her and I really hope she can’t sense how sad momma is today. I thought of buying new clothes but I cried at the thought of it idk.