Dad Commented I'm Too Old to Have Another Baby-38 YRS OLD

My dad came to visit us and his 3 gr old grandson last night and mentioned that he met a grandmother to be at a 2nd hand store looking for baby furniture. My dad comments to her "im sure my daughter has plenty she can sell you". i told dad i wasn't interested in selling anything and he's like "why- are you trying again?" i told him yes. He's like "you're too old". I'm like" who says im too old- you? thats you're opinion and thats between us- not you". i knew he wouldn't be that supportive once he found out. to be honest we've been ttc for 2 yrs now- its no one else's business - especially if their not going to be supportive.