Unprotected sex 4weeks ago.test was -ve.got periods bt nt sure if its my period or spotting during pregnancy.but my lower tummy is big.is that normal?

Depends on question: The question asked is, "Is that normal?" If one is not pregnant, her lower tummy should not be big when it wasn't big a short time ago. For it to get big, there is usually something in there, such as extra stool (constipation), extra bowel gas, extra fat (eating more calories ), or something else. If worried about pregnancy, and the next NORMAL period doesn't come, one can repeat a preg. test.