is less likely in the current scenario. The symptoms are more likely to be due to the depo-shot. Weight gain and stomach ache can be seen while on hormonal contraception
. After having normal periods after the intercourse, there is usually no need to worry about pregnancy. If you still want to exclude, you should go for the serum beta-hCG
assay along with a pelvic/trans-vaginal sonogram and see a specialist for further management. Hope this helps.