I think i'm pregnant but still getting periods. would an otc test work? or would the hormones be to wonky

If you are really: Pregnant, then the hpt would be effective and accurate. Your doctor can also do more sophisticated testing if you desire.

Regular periods?: If a woman gets regular normal periods, the urine pregnancy test will still work fine... And will give a negative result because she is not pregnant. She cannot be pregnant and also have regular normal periods, but she might have recently conceived 2 weeks after the last normal period (the urine test would also be negative, but due to testing too soon). Best to test 1 week after missing a period.