If your periods have been regular earlier and this has been an isolated episode of missing periods then we can safely assume that the corpus luteum has been under degeneration in the last week of the cycle, and if you have sex a day post missed period then the chances of pregnancy are negligible .
The symptoms you are experiencing are probably premenstrual syndrome and your menses should ensue in few days, but as you have already crossed 7 days post missed period , it is a safe practice to perform a urine pregnancy teat from early morning urine sample to confirmatively rule out pregnancy and if negative , then can patiently wait for menses to return.
I hope i have answered your query in detail,
wishing you good health,
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