4th day of missed period (30 day cycle). getting pregnancy symptoms but negative hpt (strip). also have uti. how soon can i take a blood test.?

Now: You can have it anytime now. As soon as implantation occurs the bhcg levels start to rise. See your doctor and, just in case, start taking Folic Acid supplements.

Try another test: Most hpts are pretty sensitive and should be positive by a missed period. A negative hpt, assuming it was done correctly, is pretty accurate. If you are concerned it was false, you can do another one 48 hours later. This will save you a blood test. Two negative tests make it pretty clear it's negative. Symptoms may actually be the start of a cycle as well. The UTI shouldn't interfere with this.