Had sex went for walk was in agony! Managed to get home lay down its been about 2 hours now and I'm…

Had sex went for walk was in agony! Managed to get home lay down its been about 2 hours now and I'm having dull back pains happening every 4 minutes like the start of a period coming in due tomorrow ? What shall I do they don't feel bad enough to be full blown contractions but they happening every 4 minutes?