Extremely far off due date

💙Mia • Cajun & Proud, Conservative, wife to Royce 4.12.14 ❤️, mother to Bennett 8.12.15 💙
A good friend of mine just told me that his baby mama is due sometime in April. He told me that they had sex while on vacation the first week of June and have had sex since. 
Does anyone else think that if they conceived the first week of June, that her due date should be in February, not April? I'm just curious.