Late and negative

Im late by about 4 days now, but the test was negative (twice) this past weekend. I just got off the pill in February to re-regulate before we start trying later this summer and we have been super strict with using condoms . I was running a lot and did a half marathon at the beginning of May. That was a super stress on my body, so I wonder if that’s what’s messing with things. I was pretty regular at 28-29 days before that. Feeling a bit out of sorts. Anyone else had running throw off their cycle? I haven’t really been running anymore since the race. Or should I repeat the pregnancy test again if there’s still no period in the next day or so? 🤷🏻‍♀️