We have been trying to conceive and I had sex two days (one time each day) before my period. I tracked my ovulation days and I had gotten my period as planned but it was strange, yes I had my period but it was extremely light but painful and its normally seven days long this time it was five. After my period I took a test but it came out negative. But now I'm feeling sick and I get dizzy really easily and I'm constantly tired could I be pregnant?
Having sex just before your period it is unlikely you will conceive. You are at your lowest fertility.
Ideally you'd have sex just BEFORE you ovulate. This occurs sometime between days 11 and 16 of your cycle. Day 1 is when your period starts. Sperm can survive about 5 days, the egg for 48 hours.
Your ovulation app should indicate approximately when you'll ovulate, again, about two weeks before your period.
Testing early false negatives are common. You can always retest.
Good luck, hope it helps.