LH surge

I have a question about the surge . Say it lasts two-three days, does this mean you will ovulate after the last positive ? I usually never get a long surge but lately I had a surge for over 48 hours the past two cycles after my miscarriage . Been BD naturally anyways. Last cycle I noticed my period came 2 weeks after I had my last positive so i’m thinking I must have ovulated when I stopped testing positive . IDK anymore 😭😭