Late period but my partner had a vasectomy...

Okay so... I need some advice.. my man had gotten fixed back in November but my period is close to 2 weeks late and my nipples are sore and puffy and my boobs are starting to get veiny... I don’t want to take a test yet because it is very early so does anyone have any stories of vasectomies not working? Or have any suggestions as to why my period is so late?